{
"metadata": {
"language": "Julia",
"name": ""
},
"nbformat": 3,
"nbformat_minor": 0,
"worksheets": [
{
"cells": [
{
"cell_type": "markdown",
"metadata": {},
"source": [
"#1. PLEAC Julia: Strings\n",
"[PLEAC = Language Examples Alike Cookbook](http://pleac.sourceforge.net/)\n",
"PLEAC examples are drawn from the \"Perl Cookbook\" by Tom Christiansen & Nathan Torkington, published by O'Reilly. They provide a nice range of examples oriented toward data munging, the type of work I tend to want to do first when learning a new language.\n",
"\n",
"The Julia examples below are principally translations from the [Python version](http://pleac.sourceforge.net/pleac_python/strings.html)\n",
"\n",
"### Caution\n",
"I'm learning as I go, so the code below probably doesn't represent best practice. Your suggestions are welcome! \n",
"Please file an issue or make a pull request to the [github repo](https://github.com/catawbasam/IJulia_PLEAC/).\n",
"\n",
"### Why isn't this in the main PLEAC repo?\n",
"IJulia_PLEAC uses IJulia notebook, whose format appears to be incompatible with the PLEAC file format.\n",
"\n",
"The examples are not complete. Missing items are generally noted in comments. "
]
},
{
"cell_type": "markdown",
"metadata": {},
"source": [
"## PLEAC 1.0: Introduction\n",
"Let's try out some string literals."
]
},
{
"cell_type": "code",
"collapsed": false,
"input": [
"mystr = \"\\n\" # a string containing 1 character, which is a newline"
],
"language": "python",
"metadata": {},
"outputs": [
{
"metadata": {},
"output_type": "pyout",
"prompt_number": 12,
"text": [
"\"\\n\""
]
}
],
"prompt_number": 12
},
{
"cell_type": "code",
"collapsed": false,
"input": [
"mystr = \"\\\\\\n\" # two characters, \\ and n"
],
"language": "python",
"metadata": {},
"outputs": [
{
"metadata": {},
"output_type": "pyout",
"prompt_number": 13,
"text": [
"\"\\\\\\n\""
]
}
],
"prompt_number": 13
},
{
"cell_type": "code",
"collapsed": false,
"input": [
"length(mystr)==2"
],
"language": "python",
"metadata": {},
"outputs": [
{
"metadata": {},
"output_type": "pyout",
"prompt_number": 14,
"text": [
"true"
]
}
],
"prompt_number": 14
},
{
"cell_type": "code",
"collapsed": false,
"input": [
"mystr = \"Jon 'Maddog' Orwant\" # literal single quote inside double quotes"
],
"language": "python",
"metadata": {},
"outputs": [
{
"metadata": {},
"output_type": "pyout",
"prompt_number": 15,
"text": [
"\"Jon 'Maddog' Orwant\""
]
}
],
"prompt_number": 15
},
{
"cell_type": "code",
"collapsed": false,
"input": [
"mystr = \"\"\"Jon \"Maddog\" Orwant\"\"\" # literal double quote inside triple quotes"
],
"language": "python",
"metadata": {},
"outputs": [
{
"metadata": {},
"output_type": "pyout",
"prompt_number": 16,
"text": [
"\"Jon \\\"Maddog\\\" Orwant\""
]
}
],
"prompt_number": 16
},
{
"cell_type": "code",
"collapsed": false,
"input": [
"mystr = \"Jon \\\"Maddog\\\" Orwant\" # escaped double quote"
],
"language": "python",
"metadata": {},
"outputs": [
{
"metadata": {},
"output_type": "pyout",
"prompt_number": 17,
"text": [
"\"Jon \\\"Maddog\\\" Orwant\""
]
}
],
"prompt_number": 17
},
{
"cell_type": "code",
"collapsed": false,
"input": [
"mystr = \"\"\"\n",
"This is a multiline string literal\n",
"enclosed in triple double quotes.\n",
"\"\"\""
],
"language": "python",
"metadata": {},
"outputs": [
{
"metadata": {},
"output_type": "pyout",
"prompt_number": 18,
"text": [
"\"This is a multiline string literal\\nenclosed in triple double quotes.\\n\""
]
}
],
"prompt_number": 18
},
{
"cell_type": "code",
"collapsed": false,
"input": [
"#julia does not currently have an equivalent to python docstringss, but triple-quoted comments are allowed\n",
"function fn(x)\n",
" \"\"\"we can put a comment here\"\"\"\n",
" return 2x\n",
"end\n",
"\n",
"fn(3)"
],
"language": "python",
"metadata": {},
"outputs": [
{
"metadata": {},
"output_type": "pyout",
"prompt_number": 155,
"text": [
"6"
]
}
],
"prompt_number": 155
},
{
"cell_type": "markdown",
"metadata": {},
"source": [
"##PLEAC 1.1: Accessing Substrings"
]
},
{
"cell_type": "code",
"collapsed": false,
"input": [
"offset=2; count=3;\n",
"mystr[offset:offset+count]"
],
"language": "python",
"metadata": {},
"outputs": [
{
"metadata": {},
"output_type": "pyout",
"prompt_number": 19,
"text": [
"\"his \""
]
}
],
"prompt_number": 19
},
{
"cell_type": "code",
"collapsed": false,
"input": [
"mystr[offset:] # offset to end"
],
"language": "python",
"metadata": {},
"outputs": [
{
"metadata": {},
"output_type": "pyout",
"prompt_number": 20,
"text": [
"\"his is a multiline string literal\\nenclosed in triple double quotes.\\n\""
]
}
],
"prompt_number": 20
},
{
"cell_type": "markdown",
"metadata": {},
"source": [
"#### Get a 5-char string, skip 3, then grab 2 8-char strings, then the rest"
]
},
{
"cell_type": "code",
"collapsed": false,
"input": [
"data = b\"abcdefghijklmnopqrstuvwxyz\"; # byte array 0x61-0x7a\n",
"leading, s1, s2, trailing = data[1:5], data[9:16], data[17:24], data[25:]"
],
"language": "python",
"metadata": {},
"outputs": [
{
"metadata": {},
"output_type": "pyout",
"prompt_number": 21,
"text": [
"([0x61,0x62,0x63,0x64,0x65],[0x69,0x6a,0x6b,0x6c,0x6d,0x6e,0x6f,0x70],[0x71,0x72,0x73,0x74,0x75,0x76,0x77,0x78],[0x79,0x7a])"
]
}
],
"prompt_number": 21
},
{
"cell_type": "markdown",
"metadata": {},
"source": [
"#### Split at five-char boundaries"
]
},
{
"cell_type": "code",
"collapsed": false,
"input": [
"typeof(data)"
],
"language": "python",
"metadata": {},
"outputs": [
{
"metadata": {},
"output_type": "pyout",
"prompt_number": 22,
"text": [
"Array{Uint8,1}"
]
}
],
"prompt_number": 22
},
{
"cell_type": "code",
"collapsed": false,
"input": [
"a=Array{Uint8,1}[]"
],
"language": "python",
"metadata": {},
"outputs": [
{
"metadata": {},
"output_type": "pyout",
"prompt_number": 23,
"text": [
"0-element Array{Array{Uint8,1},1}"
]
}
],
"prompt_number": 23
},
{
"cell_type": "code",
"collapsed": false,
"input": [
"push!(a,data[1:5])"
],
"language": "python",
"metadata": {},
"outputs": [
{
"metadata": {},
"output_type": "pyout",
"prompt_number": 24,
"text": [
"1-element Array{Array{Uint8,1},1}:\n",
" [0x61,0x62,0x63,0x64,0x65]"
]
}
],
"prompt_number": 24
},
{
"cell_type": "code",
"collapsed": false,
"input": [
"i=1\n",
"count=5\n",
"fivers=Array{Uint8,1}[] # 1 dimensional array of bytearrays\n",
"while i<=length(data)\n",
" chunk = data[ i : min(i+4,length(data)) ]\n",
" push!(fivers, chunk )\n",
" i=i+count\n",
"end\n",
"fivers"
],
"language": "python",
"metadata": {},
"outputs": [
{
"metadata": {},
"output_type": "pyout",
"prompt_number": 25,
"text": [
"6-element Array{Array{Uint8,1},1}:\n",
" [0x61,0x62,0x63,0x64,0x65]\n",
" [0x66,0x67,0x68,0x69,0x6a]\n",
" [0x6b,0x6c,0x6d,0x6e,0x6f]\n",
" [0x70,0x71,0x72,0x73,0x74]\n",
" [0x75,0x76,0x77,0x78,0x79]\n",
" [0x7a] "
]
}
],
"prompt_number": 25
},
{
"cell_type": "markdown",
"metadata": {},
"source": [
"####index to sub-string"
]
},
{
"cell_type": "code",
"collapsed": false,
"input": [
"mystr = \"This is what you have\"\n",
"# julia indexes are 1-based\n",
"first = mystr[1] # \"T\""
],
"language": "python",
"metadata": {},
"outputs": [
{
"metadata": {},
"output_type": "pyout",
"prompt_number": 26,
"text": [
"'T'"
]
}
],
"prompt_number": 26
},
{
"cell_type": "code",
"collapsed": false,
"input": [
"start = mystr[6:7] # \"is\""
],
"language": "python",
"metadata": {},
"outputs": [
{
"metadata": {},
"output_type": "pyout",
"prompt_number": 27,
"text": [
"\"is\""
]
}
],
"prompt_number": 27
},
{
"cell_type": "code",
"collapsed": false,
"input": [
"rest = mystr[14:] # \"you have\""
],
"language": "python",
"metadata": {},
"outputs": [
{
"metadata": {},
"output_type": "pyout",
"prompt_number": 28,
"text": [
"\"you have\""
]
}
],
"prompt_number": 28
},
{
"cell_type": "code",
"collapsed": false,
"input": [
"last = mystr[end:] # \"e\" a string"
],
"language": "python",
"metadata": {},
"outputs": [
{
"metadata": {},
"output_type": "pyout",
"prompt_number": 29,
"text": [
"\"e\""
]
}
],
"prompt_number": 29
},
{
"cell_type": "code",
"collapsed": false,
"input": [
"mystr[end] #a char"
],
"language": "python",
"metadata": {},
"outputs": [
{
"metadata": {},
"output_type": "pyout",
"prompt_number": 30,
"text": [
"'e'"
]
}
],
"prompt_number": 30
},
{
"cell_type": "code",
"collapsed": false,
"input": [
"mystr[end-1] #a char"
],
"language": "python",
"metadata": {},
"outputs": [
{
"metadata": {},
"output_type": "pyout",
"prompt_number": 31,
"text": [
"'v'"
]
}
],
"prompt_number": 31
},
{
"cell_type": "code",
"collapsed": false,
"input": [
"end4 = mystr[end-3:] # \"have\""
],
"language": "python",
"metadata": {},
"outputs": [
{
"metadata": {},
"output_type": "pyout",
"prompt_number": 32,
"text": [
"\"have\""
]
}
],
"prompt_number": 32
},
{
"cell_type": "code",
"collapsed": false,
"input": [
"piece = mystr[end-7:end-4] # \"you\""
],
"language": "python",
"metadata": {},
"outputs": [
{
"metadata": {},
"output_type": "pyout",
"prompt_number": 33,
"text": [
"\"you \""
]
}
],
"prompt_number": 33
},
{
"cell_type": "code",
"collapsed": false,
"input": [
"mystr[1:10]"
],
"language": "python",
"metadata": {},
"outputs": [
{
"metadata": {},
"output_type": "pyout",
"prompt_number": 34,
"text": [
"\"This is wh\""
]
}
],
"prompt_number": 34
},
{
"cell_type": "code",
"collapsed": false,
"input": [
"mystr[10+1:end]"
],
"language": "python",
"metadata": {},
"outputs": [
{
"metadata": {},
"output_type": "pyout",
"prompt_number": 35,
"text": [
"\"at you have\""
]
}
],
"prompt_number": 35
},
{
"cell_type": "markdown",
"metadata": {},
"source": [
"#### replace substr"
]
},
{
"cell_type": "code",
"collapsed": false,
"input": [
"replace(mystr, \" is \", \" wasn't \")"
],
"language": "python",
"metadata": {},
"outputs": [
{
"metadata": {},
"output_type": "pyout",
"prompt_number": 36,
"text": [
"\"This wasn't what you have\""
]
}
],
"prompt_number": 36
},
{
"cell_type": "markdown",
"metadata": {},
"source": [
"#### test for substr"
]
},
{
"cell_type": "code",
"collapsed": false,
"input": [
"txt = \"at\"\n",
"contains(mystr,txt)"
],
"language": "python",
"metadata": {},
"outputs": [
{
"metadata": {},
"output_type": "pyout",
"prompt_number": 37,
"text": [
"true"
]
}
],
"prompt_number": 37
},
{
"cell_type": "code",
"collapsed": false,
"input": [
"beginswith(mystr, txt)"
],
"language": "python",
"metadata": {},
"outputs": [
{
"metadata": {},
"output_type": "pyout",
"prompt_number": 38,
"text": [
"false"
]
}
],
"prompt_number": 38
},
{
"cell_type": "code",
"collapsed": false,
"input": [
"endswith(mystr,txt)"
],
"language": "python",
"metadata": {},
"outputs": [
{
"metadata": {},
"output_type": "pyout",
"prompt_number": 39,
"text": [
"false"
]
}
],
"prompt_number": 39
},
{
"cell_type": "markdown",
"metadata": {},
"source": [
"##PLEAC 1.2: Establishing a Default Value"
]
},
{
"cell_type": "markdown",
"metadata": {},
"source": [
"####Background - checking for state of a variable."
]
},
{
"cell_type": "code",
"collapsed": false,
"input": [
"isdefined(:astr) "
],
"language": "python",
"metadata": {},
"outputs": [
{
"metadata": {},
"output_type": "pyout",
"prompt_number": 40,
"text": [
"false"
]
}
],
"prompt_number": 40
},
{
"cell_type": "code",
"collapsed": false,
"input": [
"astr=None"
],
"language": "python",
"metadata": {},
"outputs": [
{
"metadata": {},
"output_type": "pyout",
"prompt_number": 41,
"text": [
"None"
]
}
],
"prompt_number": 41
},
{
"cell_type": "code",
"collapsed": false,
"input": [
"astr == None "
],
"language": "python",
"metadata": {},
"outputs": [
{
"metadata": {},
"output_type": "pyout",
"prompt_number": 42,
"text": [
"true"
]
}
],
"prompt_number": 42
},
{
"cell_type": "code",
"collapsed": false,
"input": [
"isdefined(:astr) # defined but None"
],
"language": "python",
"metadata": {},
"outputs": [
{
"metadata": {},
"output_type": "pyout",
"prompt_number": 43,
"text": [
"true"
]
}
],
"prompt_number": 43
},
{
"cell_type": "code",
"collapsed": false,
"input": [
":(astr)"
],
"language": "python",
"metadata": {},
"outputs": [
{
"metadata": {},
"output_type": "pyout",
"prompt_number": 44,
"text": [
":astr"
]
}
],
"prompt_number": 44
},
{
"cell_type": "markdown",
"metadata": {},
"source": [
"#### Haven't found an existing function to do this:"
]
},
{
"cell_type": "code",
"collapsed": false,
"input": [
"function isassigned(myvar::Symbol)\n",
" \"\"\"return true if the Symbol is defined and not None\"\"\"\n",
" DEBUG=false\n",
" if DEBUG println( :(myvar) ) end\n",
" if DEBUG println( isdefined(myvar) ) end\n",
" if isdefined(myvar) \n",
" varval = eval(myvar);\n",
" if DEBUG println( \"varval $varval\" ) end\n",
" if varval==None \n",
" if DEBUG println( \"$myvar==None \") end\n",
" return false\n",
" elseif varval==\"\" \n",
" if DEBUG println( \"\"\"$myvar==\"\" \"\"\") end\n",
" return false\n",
" else\n",
" if DEBUG println(\"$myvar has an assigned value\") end\n",
" return true\n",
" end\n",
" else\n",
" if DEBUG println(\"not defined\") end\n",
" return false\n",
" end\n",
"end"
],
"language": "python",
"metadata": {},
"outputs": [
{
"metadata": {},
"output_type": "pyout",
"prompt_number": 45,
"text": [
"isassigned (generic function with 1 method)"
]
}
],
"prompt_number": 45
},
{
"cell_type": "code",
"collapsed": false,
"input": [
"isassigned( :nosuchvar )"
],
"language": "python",
"metadata": {},
"outputs": [
{
"metadata": {},
"output_type": "pyout",
"prompt_number": 46,
"text": [
"false"
]
}
],
"prompt_number": 46
},
{
"cell_type": "code",
"collapsed": false,
"input": [
"isassigned( :astr )"
],
"language": "python",
"metadata": {},
"outputs": [
{
"metadata": {},
"output_type": "pyout",
"prompt_number": 47,
"text": [
"false"
]
}
],
"prompt_number": 47
},
{
"cell_type": "code",
"collapsed": false,
"input": [
"ex=999\n",
"isassigned(:ex)"
],
"language": "python",
"metadata": {},
"outputs": [
{
"metadata": {},
"output_type": "pyout",
"prompt_number": 48,
"text": [
"true"
]
}
],
"prompt_number": 48
},
{
"cell_type": "markdown",
"metadata": {},
"source": [
"####Setting a default value"
]
},
{
"cell_type": "code",
"collapsed": false,
"input": [
"mydefault = \"blah\""
],
"language": "python",
"metadata": {},
"outputs": [
{
"metadata": {},
"output_type": "pyout",
"prompt_number": 49,
"text": [
"\"blah\""
]
}
],
"prompt_number": 49
},
{
"cell_type": "code",
"collapsed": false,
"input": [
"ystr = isdefined(:(astr)) & (astr!=None) ? astr : mydefault \n",
"ystr"
],
"language": "python",
"metadata": {},
"outputs": [
{
"metadata": {},
"output_type": "pyout",
"prompt_number": 50,
"text": [
"\"blah\""
]
}
],
"prompt_number": 50
},
{
"cell_type": "code",
"collapsed": false,
"input": [
"ystr = isassigned(:astr) ? astr : mydefault"
],
"language": "python",
"metadata": {},
"outputs": [
{
"metadata": {},
"output_type": "pyout",
"prompt_number": 51,
"text": [
"\"blah\""
]
}
],
"prompt_number": 51
},
{
"cell_type": "markdown",
"metadata": {},
"source": [
"#### if myvar is returned from a function and may be empty/None, then use:"
]
},
{
"cell_type": "code",
"collapsed": false,
"input": [
"function f(x::Int)\n",
" \"\"\"a function that can return None\"\"\" \n",
" y = (x==4) ? x : None \n",
" return y\n",
"end"
],
"language": "python",
"metadata": {},
"outputs": [
{
"metadata": {},
"output_type": "pyout",
"prompt_number": 52,
"text": [
"f (generic function with 1 method)"
]
}
],
"prompt_number": 52
},
{
"cell_type": "code",
"collapsed": false,
"input": [
"myvar = f(3)\n",
"myvar== (myvar==None) ? \"blah\" : myvar"
],
"language": "python",
"metadata": {},
"outputs": [
{
"metadata": {},
"output_type": "pyout",
"prompt_number": 53,
"text": [
"None"
]
}
],
"prompt_number": 53
},
{
"cell_type": "markdown",
"metadata": {},
"source": [
"#### if you want a default value that can be overridden by the person calling your code, you can often wrap it in a function with a named parameter:"
]
},
{
"cell_type": "code",
"collapsed": false,
"input": [
"function fdef(prefix=\"pre\")\n",
" \"\"\"a function that can return None\"\"\" \n",
" prefix * \" duh\"\n",
"end"
],
"language": "python",
"metadata": {},
"outputs": [
{
"metadata": {},
"output_type": "pyout",
"prompt_number": 54,
"text": [
"fdef (generic function with 2 methods)"
]
}
],
"prompt_number": 54
},
{
"cell_type": "code",
"collapsed": false,
"input": [
"fdef(\"asd\")"
],
"language": "python",
"metadata": {},
"outputs": [
{
"metadata": {},
"output_type": "pyout",
"prompt_number": 55,
"text": [
"\"asd duh\""
]
}
],
"prompt_number": 55
},
{
"cell_type": "code",
"collapsed": false,
"input": [
"fdef()"
],
"language": "python",
"metadata": {},
"outputs": [
{
"metadata": {},
"output_type": "pyout",
"prompt_number": 56,
"text": [
"\"pre duh\""
]
}
],
"prompt_number": 56
},
{
"cell_type": "code",
"collapsed": false,
"input": [
"# use b if b is defined, else c\n",
"a = isdefined(:b) ? b : 21"
],
"language": "python",
"metadata": {},
"outputs": [
{
"metadata": {},
"output_type": "pyout",
"prompt_number": 57,
"text": [
"21"
]
}
],
"prompt_number": 57
},
{
"cell_type": "code",
"collapsed": false,
"input": [
"ENV[\"USERNAME\"]"
],
"language": "python",
"metadata": {},
"outputs": [
{
"metadata": {},
"output_type": "pyout",
"prompt_number": 58,
"text": [
"\"KEITHC\""
]
}
],
"prompt_number": 58
},
{
"cell_type": "code",
"collapsed": false,
"input": [
"haskey(ENV,\"USERNAME\")"
],
"language": "python",
"metadata": {},
"outputs": [
{
"metadata": {},
"output_type": "pyout",
"prompt_number": 59,
"text": [
"true"
]
}
],
"prompt_number": 59
},
{
"cell_type": "code",
"collapsed": false,
"input": [
"function get_username()\n",
" if haskey(ENV,\"USERNAME\") \n",
" usr=ENV[\"USERNAME\"]\n",
" elseif haskey(ENV,\"LOGNAME\") \n",
" usr=ENV[\"LOGNAME\"]\n",
" elseif haskey(ENV,\"USER\") \n",
" usr=ENV[\"USER\"] \n",
" else \n",
" usr = None\n",
" end\n",
" return usr\n",
"end"
],
"language": "python",
"metadata": {},
"outputs": [
{
"metadata": {},
"output_type": "pyout",
"prompt_number": 60,
"text": [
"get_username (generic function with 1 method)"
]
}
],
"prompt_number": 60
},
{
"cell_type": "code",
"collapsed": false,
"input": [
"get_username()"
],
"language": "python",
"metadata": {},
"outputs": [
{
"metadata": {},
"output_type": "pyout",
"prompt_number": 61,
"text": [
"\"KEITHC\""
]
}
],
"prompt_number": 61
},
{
"cell_type": "markdown",
"metadata": {},
"source": [
"##PLEAC 1.3: Exchanging values without Using Temporary Variables"
]
},
{
"cell_type": "code",
"collapsed": false,
"input": [
"# v1, v2 = v2, v1\n",
"x, y = (4, 3);"
],
"language": "python",
"metadata": {},
"outputs": [],
"prompt_number": 61
},
{
"cell_type": "code",
"collapsed": false,
"input": [
"x"
],
"language": "python",
"metadata": {},
"outputs": [
{
"metadata": {},
"output_type": "pyout",
"prompt_number": 62,
"text": [
"4"
]
}
],
"prompt_number": 62
},
{
"cell_type": "code",
"collapsed": false,
"input": [
"y"
],
"language": "python",
"metadata": {},
"outputs": [
{
"metadata": {},
"output_type": "pyout",
"prompt_number": 63,
"text": [
"3"
]
}
],
"prompt_number": 63
},
{
"cell_type": "code",
"collapsed": false,
"input": [
"one, two, three = split(\"January March August\")"
],
"language": "python",
"metadata": {},
"outputs": [
{
"metadata": {},
"output_type": "pyout",
"prompt_number": 64,
"text": [
"3-element Array{String,1}:\n",
" \"January\"\n",
" \"March\" \n",
" \"August\" "
]
}
],
"prompt_number": 64
},
{
"cell_type": "code",
"collapsed": false,
"input": [
"[one, two, three]'"
],
"language": "python",
"metadata": {},
"outputs": [
{
"metadata": {},
"output_type": "pyout",
"prompt_number": 65,
"text": [
"1x3 Array{ASCIIString,2}:\n",
" \"January\" \"March\" \"August\""
]
}
],
"prompt_number": 65
},
{
"cell_type": "code",
"collapsed": false,
"input": [
"one, two, three = two, three, one"
],
"language": "python",
"metadata": {},
"outputs": [
{
"metadata": {},
"output_type": "pyout",
"prompt_number": 66,
"text": [
"(\"March\",\"August\",\"January\")"
]
}
],
"prompt_number": 66
},
{
"cell_type": "code",
"collapsed": false,
"input": [
"one"
],
"language": "python",
"metadata": {},
"outputs": [
{
"metadata": {},
"output_type": "pyout",
"prompt_number": 67,
"text": [
"\"March\""
]
}
],
"prompt_number": 67
},
{
"cell_type": "markdown",
"metadata": {},
"source": [
"##PLEAC 1.4: Converting between ASCII Characters and Values"
]
},
{
"cell_type": "code",
"collapsed": false,
"input": [
"char = 'a'"
],
"language": "python",
"metadata": {},
"outputs": [
{
"metadata": {},
"output_type": "pyout",
"prompt_number": 68,
"text": [
"'a'"
]
}
],
"prompt_number": 68
},
{
"cell_type": "code",
"collapsed": false,
"input": [
"ascii_value = int(char)"
],
"language": "python",
"metadata": {},
"outputs": [
{
"metadata": {},
"output_type": "pyout",
"prompt_number": 69,
"text": [
"97"
]
}
],
"prompt_number": 69
},
{
"cell_type": "code",
"collapsed": false,
"input": [
"Base.char(120) # char(120) should work but I'm getting a namespace collision"
],
"language": "python",
"metadata": {},
"outputs": [
{
"metadata": {},
"output_type": "pyout",
"prompt_number": 70,
"text": [
"'x'"
]
}
],
"prompt_number": 70
},
{
"cell_type": "code",
"collapsed": false,
"input": [
"println(\"number $(int(char)) is character '$char'\")"
],
"language": "python",
"metadata": {},
"outputs": [
{
"output_type": "stream",
"stream": "stdout",
"text": [
"number 97 is character 'a'"
]
},
{
"output_type": "stream",
"stream": "stdout",
"text": [
"\n"
]
}
],
"prompt_number": 71
},
{
"cell_type": "code",
"collapsed": false,
"input": [
"ascii_character_numbers = [int(c) for c in \"sample\"]"
],
"language": "python",
"metadata": {},
"outputs": [
{
"metadata": {},
"output_type": "pyout",
"prompt_number": 72,
"text": [
"6-element Array{Int64,1}:\n",
" 115\n",
" 97\n",
" 109\n",
" 112\n",
" 108\n",
" 101"
]
}
],
"prompt_number": 72
},
{
"cell_type": "code",
"collapsed": false,
"input": [
"join([c for c in \"sample\"],\"\")"
],
"language": "python",
"metadata": {},
"outputs": [
{
"metadata": {},
"output_type": "pyout",
"prompt_number": 73,
"text": [
"\"sample\""
]
}
],
"prompt_number": 73
},
{
"cell_type": "code",
"collapsed": false,
"input": [
"join([Base.char(i) for i in ascii_character_numbers],\"\")"
],
"language": "python",
"metadata": {},
"outputs": [
{
"metadata": {},
"output_type": "pyout",
"prompt_number": 74,
"text": [
"\"sample\""
]
}
],
"prompt_number": 74
},
{
"cell_type": "code",
"collapsed": false,
"input": [
"hal=\"HAL\"\n",
"join([Base.char(int(i)+1) for i in hal],\"\")"
],
"language": "python",
"metadata": {},
"outputs": [
{
"metadata": {},
"output_type": "pyout",
"prompt_number": 75,
"text": [
"\"IBM\""
]
}
],
"prompt_number": 75
},
{
"cell_type": "markdown",
"metadata": {},
"source": [
"##PLEAC 1.5: Processing a String one Character at a Time"
]
},
{
"cell_type": "code",
"collapsed": false,
"input": [
"myarray = [c for c in \"whatever\"]'"
],
"language": "python",
"metadata": {},
"outputs": [
{
"metadata": {},
"output_type": "pyout",
"prompt_number": 76,
"text": [
"1x8 Array{Char,2}:\n",
" 'w' 'h' 'a' 't' 'e' 'v' 'e' 'r'"
]
}
],
"prompt_number": 76
},
{
"cell_type": "code",
"collapsed": false,
"input": [
"for mychar in \"whatever\"\n",
" println(mychar)\n",
"end"
],
"language": "python",
"metadata": {},
"outputs": [
{
"output_type": "stream",
"stream": "stdout",
"text": [
"w"
]
},
{
"output_type": "stream",
"stream": "stdout",
"text": [
"\n",
"h\n",
"a\n",
"t\n",
"e\n",
"v\n",
"e\n",
"r\n"
]
}
],
"prompt_number": 77
},
{
"cell_type": "code",
"collapsed": false,
"input": [
"cset = Set([c for c in \"Whatever\"]...)"
],
"language": "python",
"metadata": {},
"outputs": [
{
"metadata": {},
"output_type": "pyout",
"prompt_number": 78,
"text": [
"Set{Char}('r','a','h','W','v','t','e')"
]
}
],
"prompt_number": 78
},
{
"cell_type": "code",
"collapsed": false,
"input": [
"split(\"whatever\",\"\")'"
],
"language": "python",
"metadata": {},
"outputs": [
{
"metadata": {},
"output_type": "pyout",
"prompt_number": 79,
"text": [
"1x8 Array{String,2}:\n",
" \"w\" \"h\" \"a\" \"t\" \"e\" \"v\" \"e\" \"r\""
]
}
],
"prompt_number": 79
},
{
"cell_type": "code",
"collapsed": false,
"input": [
"sset =Set( split(\"whatever\",\"\")... )"
],
"language": "python",
"metadata": {},
"outputs": [
{
"metadata": {},
"output_type": "pyout",
"prompt_number": 80,
"text": [
"Set{ASCIIString}(\"a\",\"e\",\"r\",\"v\",\"w\",\"t\",\"h\")"
]
}
],
"prompt_number": 80
},
{
"cell_type": "code",
"collapsed": false,
"input": [
"csort = sort([c for c in cset])'"
],
"language": "python",
"metadata": {},
"outputs": [
{
"metadata": {},
"output_type": "pyout",
"prompt_number": 81,
"text": [
"1x7 Array{Any,2}:\n",
" 'W' 'a' 'e' 'h' 'r' 't' 'v'"
]
}
],
"prompt_number": 81
},
{
"cell_type": "code",
"collapsed": false,
"input": [
"println(\"unique chars are: \", join(csort,\",\"))"
],
"language": "python",
"metadata": {},
"outputs": [
{
"output_type": "stream",
"stream": "stdout",
"text": [
"unique chars are: "
]
},
{
"output_type": "stream",
"stream": "stdout",
"text": [
"W,a,e,h,r,t,v\n"
]
}
],
"prompt_number": 82
},
{
"cell_type": "code",
"collapsed": false,
"input": [
"mystr=\"whatever\"\n",
"ascvals= [int(c) for c in mystr];"
],
"language": "python",
"metadata": {},
"outputs": [],
"prompt_number": 82
},
{
"cell_type": "code",
"collapsed": false,
"input": [
"println(\"\"\"Total is $(sum(ascvals)) for \"$mystr\".\"\"\")"
],
"language": "python",
"metadata": {},
"outputs": [
{
"output_type": "stream",
"stream": "stdout",
"text": [
"Total is 870 for \"whatever\"."
]
},
{
"output_type": "stream",
"stream": "stdout",
"text": [
"\n"
]
}
],
"prompt_number": 83
},
{
"cell_type": "code",
"collapsed": false,
"input": [
"function checksum(mystr) \n",
" vals = [ int(c) for c in mystr ]\n",
" chksum = sum(vals) % (2^16) - 1\n",
" return chksum\n",
"end"
],
"language": "python",
"metadata": {},
"outputs": [
{
"metadata": {},
"output_type": "pyout",
"prompt_number": 84,
"text": [
"checksum (generic function with 1 method)"
]
}
],
"prompt_number": 84
},
{
"cell_type": "code",
"collapsed": false,
"input": [
"checksum(\"whatever\")"
],
"language": "python",
"metadata": {},
"outputs": [
{
"metadata": {},
"output_type": "pyout",
"prompt_number": 85,
"text": [
"869"
]
}
],
"prompt_number": 85
},
{
"cell_type": "code",
"collapsed": false,
"input": [
"fl = open(\"c:/temp/blah.txt\",\"w\")\n",
"write(fl, \"what up, gee?\")\n",
"close(fl)"
],
"language": "python",
"metadata": {},
"outputs": [],
"prompt_number": 86
},
{
"cell_type": "code",
"collapsed": false,
"input": [
"flstr = readall(\"c:/temp/blah.txt\")"
],
"language": "python",
"metadata": {},
"outputs": [
{
"metadata": {},
"output_type": "pyout",
"prompt_number": 87,
"text": [
"\"what up, gee?\""
]
}
],
"prompt_number": 87
},
{
"cell_type": "code",
"collapsed": false,
"input": [
"checksum(flstr)"
],
"language": "python",
"metadata": {},
"outputs": [
{
"metadata": {},
"output_type": "pyout",
"prompt_number": 88,
"text": [
"1140"
]
}
],
"prompt_number": 88
},
{
"cell_type": "markdown",
"metadata": {},
"source": [
"##PLEAC 1.6: Reversing a String by Word or Character"
]
},
{
"cell_type": "code",
"collapsed": false,
"input": [
"reverse([1,2,3])"
],
"language": "python",
"metadata": {},
"outputs": [
{
"metadata": {},
"output_type": "pyout",
"prompt_number": 89,
"text": [
"3-element Array{Int64,1}:\n",
" 3\n",
" 2\n",
" 1"
]
}
],
"prompt_number": 89
},
{
"cell_type": "code",
"collapsed": false,
"input": [
"reverse(\"Stuff\")"
],
"language": "python",
"metadata": {},
"outputs": [
{
"metadata": {},
"output_type": "pyout",
"prompt_number": 90,
"text": [
"\"ffutS\""
]
}
],
"prompt_number": 90
},
{
"cell_type": "code",
"collapsed": false,
"input": [
"mystr=\"a bunch of words\"\n",
"myarray = split(mystr)"
],
"language": "python",
"metadata": {},
"outputs": [
{
"metadata": {},
"output_type": "pyout",
"prompt_number": 91,
"text": [
"4-element Array{String,1}:\n",
" \"a\" \n",
" \"bunch\"\n",
" \"of\" \n",
" \"words\""
]
}
],
"prompt_number": 91
},
{
"cell_type": "code",
"collapsed": false,
"input": [
"join(reverse(myarray), \" \")"
],
"language": "python",
"metadata": {},
"outputs": [
{
"metadata": {},
"output_type": "pyout",
"prompt_number": 92,
"text": [
"\"words of bunch a\""
]
}
],
"prompt_number": 92
},
{
"cell_type": "code",
"collapsed": false,
"input": [
"word = \"reviver\"\n",
"is_palindrome = (word == reverse(word))"
],
"language": "python",
"metadata": {},
"outputs": [
{
"metadata": {},
"output_type": "pyout",
"prompt_number": 93,
"text": [
"true"
]
}
],
"prompt_number": 93
},
{
"cell_type": "markdown",
"metadata": {},
"source": [
"* skipped long palindromes"
]
},
{
"cell_type": "markdown",
"metadata": {},
"source": [
"##PLEAC 1.7: Expanding and Compressing Tabs"
]
},
{
"cell_type": "code",
"collapsed": false,
"input": [
"replace(\"adfa\\t \",'\\t',\" \")"
],
"language": "python",
"metadata": {},
"outputs": [
{
"metadata": {},
"output_type": "pyout",
"prompt_number": 94,
"text": [
"\"adfa \""
]
}
],
"prompt_number": 94
},
{
"cell_type": "code",
"collapsed": false,
"input": [
"replace(\" blah\", \" \",'\\t')"
],
"language": "python",
"metadata": {},
"outputs": [
{
"metadata": {},
"output_type": "pyout",
"prompt_number": 95,
"text": [
"\"\\t\\tblah\""
]
}
],
"prompt_number": 95
},
{
"cell_type": "markdown",
"metadata": {},
"source": [
"##PLEAC 1.8: Expanding Variables in User Input"
]
},
{
"cell_type": "code",
"collapsed": false,
"input": [
"#-----------------------------\n",
"rows=24; cols=80\n",
"text = \"I am $(rows) high and $(cols) long\"\n",
"print( text)"
],
"language": "python",
"metadata": {},
"outputs": [
{
"output_type": "stream",
"stream": "stdout",
"text": [
"I am 24 high and 80 long"
]
}
],
"prompt_number": 96
},
{
"cell_type": "code",
"collapsed": false,
"input": [
"re = r\"\\d+\""
],
"language": "python",
"metadata": {},
"outputs": [
{
"metadata": {},
"output_type": "pyout",
"prompt_number": 97,
"text": [
"r\"\\d+\""
]
}
],
"prompt_number": 97
},
{
"cell_type": "code",
"collapsed": false,
"input": [
"ismatch(re,\"Are you 43?\")"
],
"language": "python",
"metadata": {},
"outputs": [
{
"metadata": {},
"output_type": "pyout",
"prompt_number": 98,
"text": [
"true"
]
}
],
"prompt_number": 98
},
{
"cell_type": "code",
"collapsed": false,
"input": [
"ismatch(re,\"Are you XXIII?\")"
],
"language": "python",
"metadata": {},
"outputs": [
{
"metadata": {},
"output_type": "pyout",
"prompt_number": 99,
"text": [
"false"
]
}
],
"prompt_number": 99
},
{
"cell_type": "code",
"collapsed": false,
"input": [
"m=match(re,\"Are you 43?\")"
],
"language": "python",
"metadata": {},
"outputs": [
{
"metadata": {},
"output_type": "pyout",
"prompt_number": 100,
"text": [
"RegexMatch(\"43\")"
]
}
],
"prompt_number": 100
},
{
"cell_type": "code",
"collapsed": false,
"input": [
"dump(m)"
],
"language": "python",
"metadata": {},
"outputs": [
{
"output_type": "stream",
"stream": "stdout",
"text": [
"RegexMatch"
]
},
{
"output_type": "stream",
"stream": "stdout",
"text": [
" \n",
" match: SubString{UTF8String} \"43\"\n",
" captures: Array(Union(Nothing,SubString{UTF8String}),(0,)) []\n",
" offset: "
]
},
{
"output_type": "stream",
"stream": "stdout",
"text": [
"Int64 9\n",
" offsets: Array(Int64,(0,)) []\n"
]
}
],
"prompt_number": 101
},
{
"cell_type": "code",
"collapsed": false,
"input": [
"m.offset"
],
"language": "python",
"metadata": {},
"outputs": [
{
"metadata": {},
"output_type": "pyout",
"prompt_number": 102,
"text": [
"9"
]
}
],
"prompt_number": 102
},
{
"cell_type": "code",
"collapsed": false,
"input": [
"m.match"
],
"language": "python",
"metadata": {},
"outputs": [
{
"metadata": {},
"output_type": "pyout",
"prompt_number": 103,
"text": [
"\"43\""
]
}
],
"prompt_number": 103
},
{
"cell_type": "code",
"collapsed": false,
"input": [
"replace(\"Are you 23 or 43?\",re,\"xx\")"
],
"language": "python",
"metadata": {},
"outputs": [
{
"metadata": {},
"output_type": "pyout",
"prompt_number": 104,
"text": [
"\"Are you xx or xx?\""
]
}
],
"prompt_number": 104
},
{
"cell_type": "code",
"collapsed": false,
"input": [
"m.captures"
],
"language": "python",
"metadata": {},
"outputs": [
{
"metadata": {},
"output_type": "pyout",
"prompt_number": 105,
"text": [
"0-element Array{Union(Nothing,SubString{UTF8String}),1}"
]
}
],
"prompt_number": 105
},
{
"cell_type": "code",
"collapsed": false,
"input": [
"rec=r\"(\\d+)\""
],
"language": "python",
"metadata": {},
"outputs": [
{
"metadata": {},
"output_type": "pyout",
"prompt_number": 106,
"text": [
"r\"(\\d+)\""
]
}
],
"prompt_number": 106
},
{
"cell_type": "code",
"collapsed": false,
"input": [
"m=match(rec,\"Are you 43?\")\n",
"dump(m)"
],
"language": "python",
"metadata": {},
"outputs": [
{
"output_type": "stream",
"stream": "stdout",
"text": [
"RegexMatch"
]
},
{
"output_type": "stream",
"stream": "stdout",
"text": [
" \n",
" match: SubString{UTF8String} \"43\"\n",
" captures: Array(Union(Nothing,SubString{UTF8String}),(1,)) [\"43\"]\n",
" offset: Int64 9\n",
" offsets: Array(Int64,(1,)) [9]\n"
]
}
],
"prompt_number": 107
},
{
"cell_type": "code",
"collapsed": false,
"input": [
"parseint( m.captures[1])"
],
"language": "python",
"metadata": {},
"outputs": [
{
"metadata": {},
"output_type": "pyout",
"prompt_number": 108,
"text": [
"43"
]
}
],
"prompt_number": 108
},
{
"cell_type": "code",
"collapsed": false,
"input": [
"mystr = \"Are you 43?\"\n",
"m = match(rec,\"Are you 43?\")\n",
"replace(mystr, m.captures[1], string(2*parseint(m.captures[1])) )"
],
"language": "python",
"metadata": {},
"outputs": [
{
"metadata": {},
"output_type": "pyout",
"prompt_number": 109,
"text": [
"\"Are you 86?\""
]
}
],
"prompt_number": 109
},
{
"cell_type": "markdown",
"metadata": {},
"source": [
"####Safe Substitution"
]
},
{
"cell_type": "code",
"collapsed": false,
"input": [
"function default_string(string_symbol::Symbol, default=\"[Not Defined]\")\n",
" def_str= isdefined(string_symbol) ? eval(string_symbol) : \"[Not Defined]\"\n",
" return def_str\n",
"end"
],
"language": "python",
"metadata": {},
"outputs": [
{
"metadata": {},
"output_type": "pyout",
"prompt_number": 110,
"text": [
"default_string (generic function with 2 methods)"
]
}
],
"prompt_number": 110
},
{
"cell_type": "code",
"collapsed": false,
"input": [
"\"\"\"who is $(isdefined(:z) ? z : \"[Not Defined]\")\"\"\""
],
"language": "python",
"metadata": {},
"outputs": [
{
"metadata": {},
"output_type": "pyout",
"prompt_number": 111,
"text": [
"\"who is [Not Defined]\""
]
}
],
"prompt_number": 111
},
{
"cell_type": "code",
"collapsed": false,
"input": [
"\"\"\"who is $(default_string(:z))\"\"\""
],
"language": "python",
"metadata": {},
"outputs": [
{
"metadata": {},
"output_type": "pyout",
"prompt_number": 112,
"text": [
"\"who is [Not Defined]\""
]
}
],
"prompt_number": 112
},
{
"cell_type": "markdown",
"metadata": {},
"source": [
"##PLEAC 1.9: Controlling Case"
]
},
{
"cell_type": "code",
"collapsed": false,
"input": [
"uppercase(\"bo peep\")"
],
"language": "python",
"metadata": {},
"outputs": [
{
"metadata": {},
"output_type": "pyout",
"prompt_number": 113,
"text": [
"\"BO PEEP\""
]
}
],
"prompt_number": 113
},
{
"cell_type": "code",
"collapsed": false,
"input": [
"lowercase(\"Bo Peep\")"
],
"language": "python",
"metadata": {},
"outputs": [
{
"metadata": {},
"output_type": "pyout",
"prompt_number": 114,
"text": [
"\"bo peep\""
]
}
],
"prompt_number": 114
},
{
"cell_type": "code",
"collapsed": false,
"input": [
"mystr=\"bo Peep\""
],
"language": "python",
"metadata": {},
"outputs": [
{
"metadata": {},
"output_type": "pyout",
"prompt_number": 115,
"text": [
"\"bo Peep\""
]
}
],
"prompt_number": 115
},
{
"cell_type": "code",
"collapsed": false,
"input": [
"function capitalcase(mystr)\n",
" \"\"\"capitalize the first letter of each word in a string\"\"\"\n",
" return join([ucfirst(s) for s in split(mystr)], \" \")\n",
"end"
],
"language": "python",
"metadata": {},
"outputs": [
{
"metadata": {},
"output_type": "pyout",
"prompt_number": 116,
"text": [
"capitalcase (generic function with 1 method)"
]
}
],
"prompt_number": 116
},
{
"cell_type": "code",
"collapsed": false,
"input": [
"capitalcase(\"bo peep went to fetch\")"
],
"language": "python",
"metadata": {},
"outputs": [
{
"metadata": {},
"output_type": "pyout",
"prompt_number": 117,
"text": [
"\"Bo Peep Went To Fetch\""
]
}
],
"prompt_number": 117
},
{
"cell_type": "code",
"collapsed": false,
"input": [
"ucfirst(\"bo peep\")"
],
"language": "python",
"metadata": {},
"outputs": [
{
"metadata": {},
"output_type": "pyout",
"prompt_number": 118,
"text": [
"\"Bo peep\""
]
}
],
"prompt_number": 118
},
{
"cell_type": "code",
"collapsed": false,
"input": [
"#skipped random case letters"
],
"language": "python",
"metadata": {},
"outputs": [],
"prompt_number": 119
},
{
"cell_type": "markdown",
"metadata": {},
"source": [
"##PLEAC 1.10: Interpolating Functions and Expressions Within Strings"
]
},
{
"cell_type": "code",
"collapsed": false,
"input": [
"n=45\n",
"\"I have $(n + 1) guanacos.\" "
],
"language": "python",
"metadata": {},
"outputs": [
{
"metadata": {},
"output_type": "pyout",
"prompt_number": 120,
"text": [
"\"I have 46 guanacos.\""
]
}
],
"prompt_number": 120
},
{
"cell_type": "markdown",
"metadata": {},
"source": [
"Use templates from Package Mustache.jl to substitute from a dictionary. "
]
},
{
"cell_type": "code",
"collapsed": false,
"input": [
"using Mustache"
],
"language": "python",
"metadata": {},
"outputs": [],
"prompt_number": 121
},
{
"cell_type": "code",
"collapsed": false,
"input": [
"mytemplate = mt\"\n",
"To: {{address}}\n",
"From: Your Bank\n",
"CC: {{cc_number}}\n",
"Date: {{date}}\n",
"\n",
"Dear {{name}},\n",
"\n",
"Today you bounced check number {{checknum}} to us.\n",
"Your account is now closed.\n",
"\n",
"Sincerely,\n",
"the management\n",
"\""
],
"language": "python",
"metadata": {},
"outputs": [
{
"metadata": {},
"output_type": "pyout",
"prompt_number": 122,
"text": [
"MustacheTokens({{\"text\",\"\\nTo: \",0,7},{\"name\",\"address\",7,20},{\"text\",\"\\nFrom: Your Bank\\nCC: \",20,43},{\"name\",\"cc_number\",43,58},{\"text\",\"\\nDate: \",58,65},{\"name\",\"date\",65,75},{\"text\",\"\\n\\nDear \",75,82},{\"name\",\"name\",82,92},{\"text\",\",\\n\\nToday you bounced check number \",92,126},{\"name\",\"checknum\",126,140},{\"text\",\" to us.\\nYour account is now closed.\\n\\nSincerely,\\nthe management\\n\",140,203}})"
]
}
],
"prompt_number": 122
},
{
"cell_type": "code",
"collapsed": false,
"input": [
"person = {\"address\"=>\"Joe@somewhere.com\",\n",
" \"name\"=>\"Joe\",\n",
" \"date\"=>\"2012-04-22\",\n",
" \"cc_number\"=>1234567890,\n",
" \"checknum\"=> 512 \n",
" }"
],
"language": "python",
"metadata": {},
"outputs": [
{
"metadata": {},
"output_type": "pyout",
"prompt_number": 123,
"text": [
"{\"date\"=>\"2012-04-22\",\"checknum\"=>512,\"cc_number\"=>1234567890,\"address\"=>\"Joe@somewhere.com\",\"name\"=>\"Joe\"}"
]
}
],
"prompt_number": 123
},
{
"cell_type": "code",
"collapsed": false,
"input": [
"print(render(mytemplate, person))"
],
"language": "python",
"metadata": {},
"outputs": [
{
"output_type": "stream",
"stream": "stdout",
"text": [
"\n",
"To: Joe@somewhere.com\n",
"From: Your Bank\n",
"CC: 1234567890\n",
"Date: 2012-04-22\n",
"\n",
"Dear Joe,\n",
"\n",
"Today you bounced check number 512 to us.\n",
"Your account is now closed.\n",
"\n",
"Sincerely,\n",
"the management\n"
]
}
],
"prompt_number": 124
},
{
"cell_type": "markdown",
"metadata": {},
"source": [
"##PLEAC 1.11: Indenting Here Documents \n",
"indenting here documents \n",
"not clear we need to do anything --there are no leading blanks by default"
]
},
{
"cell_type": "code",
"collapsed": false,
"input": [
"var = \"\"\"\n",
" your text\n",
" goes here\n",
" \"\"\""
],
"language": "python",
"metadata": {},
"outputs": [
{
"metadata": {},
"output_type": "pyout",
"prompt_number": 125,
"text": [
"\"your text\\ngoes here\\n\""
]
}
],
"prompt_number": 125
},
{
"cell_type": "code",
"collapsed": false,
"input": [
"print(var)"
],
"language": "python",
"metadata": {},
"outputs": [
{
"output_type": "stream",
"stream": "stdout",
"text": [
"your text\n",
"goes here\n"
]
}
],
"prompt_number": 126
},
{
"cell_type": "markdown",
"metadata": {},
"source": [
"#### split into lines, use every line except first and last, left strip and rejoin."
]
},
{
"cell_type": "code",
"collapsed": false,
"input": [
"poem = \"\"\"\n",
" Here's your poem:\n",
" Now far ahead the Road has gone,\n",
" And I must follow, if I can,\n",
" Pursuing it with eager feet,\n",
" Until it joins some larger way\n",
" Where many paths and errand meet.\n",
" And whither then? I cannot say.\n",
" --Bilbo in /usr/src/perl/pp_ctl.c \n",
" \"\"\""
],
"language": "python",
"metadata": {},
"outputs": [
{
"metadata": {},
"output_type": "pyout",
"prompt_number": 127,
"text": [
"\"Here's your poem:\\nNow far ahead the Road has gone,\\n And I must follow, if I can,\\nPursuing it with eager feet,\\n Until it joins some larger way\\nWhere many paths and errand meet.\\n And whither then? I cannot say.\\n --Bilbo in /usr/src/perl/pp_ctl.c \\n\""
]
}
],
"prompt_number": 127
},
{
"cell_type": "code",
"collapsed": false,
"input": [
"print( poem)"
],
"language": "python",
"metadata": {},
"outputs": [
{
"output_type": "stream",
"stream": "stdout",
"text": [
"Here's your poem:\n",
"Now far ahead the Road has gone,\n",
" And I must follow, if I can,\n",
"Pursuing it with eager feet,\n",
" Until it joins some larger way\n",
"Where many paths and errand meet.\n",
" And whither then? I cannot say.\n",
" --Bilbo in /usr/src/perl/pp_ctl.c \n"
]
}
],
"prompt_number": 128
},
{
"cell_type": "code",
"collapsed": false,
"input": [
"print( join( [lstrip(ln) for ln in split(poem,'\\n')[2:end-2] ], \"\\n\"))"
],
"language": "python",
"metadata": {},
"outputs": [
{
"output_type": "stream",
"stream": "stdout",
"text": [
"Now far ahead the Road has gone,\n",
"And I must follow, if I can,\n",
"Pursuing it with eager feet,\n",
"Until it joins some larger way\n",
"Where many paths and errand meet.\n",
"And whither then? I cannot say."
]
}
],
"prompt_number": 129
},
{
"cell_type": "markdown",
"metadata": {},
"source": [
"##PLEAC 1.12: Reformatting Paragraphs"
]
},
{
"cell_type": "code",
"collapsed": false,
"input": [
"require(\"textwrap\")\n",
"using TextWrap"
],
"language": "python",
"metadata": {},
"outputs": [],
"prompt_number": 131
},
{
"cell_type": "code",
"collapsed": false,
"input": [
"txt = \"\"\"\\\n",
"Folding and splicing is the work of an editor,\n",
"not a mere collection of silicon\n",
"and\n",
"mobile electrons!\n",
"\"\"\""
],
"language": "python",
"metadata": {},
"outputs": [
{
"metadata": {},
"output_type": "pyout",
"prompt_number": 132,
"text": [
"\"Folding and splicing is the work of an editor,\\nnot a mere collection of silicon\\nand\\nmobile electrons!\\n\""
]
}
],
"prompt_number": 132
},
{
"cell_type": "code",
"collapsed": false,
"input": [
"print(TextWrap.wrap(txt, width=20, initial_indent=4, subsequent_indent=2))"
],
"language": "python",
"metadata": {},
"outputs": [
{
"output_type": "stream",
"stream": "stdout",
"text": [
" Folding and\n",
" splicing is the\n",
" work of an editor,\n",
" not a mere\n",
" collection of\n",
" silicon and mobile\n",
" electrons!"
]
}
],
"prompt_number": 133
},
{
"cell_type": "code",
"collapsed": false,
"input": [
"\"\"\"Expected result:\n",
"\n",
"01234567890123456789\n",
" Folding and\n",
" splicing is the\n",
" work of an editor,\n",
" not a mere\n",
" collection of\n",
" silicon and mobile\n",
" electrons!\n",
"\"\"\";"
],
"language": "python",
"metadata": {},
"outputs": [],
"prompt_number": 133
},
{
"cell_type": "code",
"collapsed": false,
"input": [
"# merge multiple lines into one, then wrap one long line -- SKIP"
],
"language": "python",
"metadata": {},
"outputs": [],
"prompt_number": 134
},
{
"cell_type": "markdown",
"metadata": {},
"source": [
"##PLEAC 1.13: Escaping Characters\n",
"Will not solve."
]
},
{
"cell_type": "markdown",
"metadata": {},
"source": [
"##PLEAC 1.14: Trimming Blanks from the Ends of a String"
]
},
{
"cell_type": "code",
"collapsed": false,
"input": [
"mystr = \" blah \""
],
"language": "python",
"metadata": {},
"outputs": [
{
"metadata": {},
"output_type": "pyout",
"prompt_number": 135,
"text": [
"\" blah \""
]
}
],
"prompt_number": 135
},
{
"cell_type": "code",
"collapsed": false,
"input": [
"lstrip(mystr)"
],
"language": "python",
"metadata": {},
"outputs": [
{
"metadata": {},
"output_type": "pyout",
"prompt_number": 136,
"text": [
"\"blah \""
]
}
],
"prompt_number": 136
},
{
"cell_type": "code",
"collapsed": false,
"input": [
"rstrip(mystr)"
],
"language": "python",
"metadata": {},
"outputs": [
{
"metadata": {},
"output_type": "pyout",
"prompt_number": 137,
"text": [
"\" blah\""
]
}
],
"prompt_number": 137
},
{
"cell_type": "code",
"collapsed": false,
"input": [
"strip(mystr)"
],
"language": "python",
"metadata": {},
"outputs": [
{
"metadata": {},
"output_type": "pyout",
"prompt_number": 138,
"text": [
"\"blah\""
]
}
],
"prompt_number": 138
},
{
"cell_type": "markdown",
"metadata": {},
"source": [
"##PLEAC 1.15: Parsing Comma-Separated Data"
]
},
{
"cell_type": "code",
"collapsed": false,
"input": [
"ezcsv = \"\"\"a,b,c\n",
" 1,2,3\n",
" 4,5,6\"\"\""
],
"language": "python",
"metadata": {},
"outputs": [
{
"metadata": {},
"output_type": "pyout",
"prompt_number": 139,
"text": [
"\"a,b,c\\n1,2,3\\n4,5,6\""
]
}
],
"prompt_number": 139
},
{
"cell_type": "code",
"collapsed": false,
"input": [
"line = \"\"\"XYZZY,\"\",\"O'Reilly, Inc\",\"Wall, Larry\",\"a \\\\\"glug\\\\\" bit,\",5,\"Error, Core Dumped,\",\"\"\""
],
"language": "python",
"metadata": {},
"outputs": [
{
"metadata": {},
"output_type": "pyout",
"prompt_number": 140,
"text": [
"\"XYZZY,\\\"\\\",\\\"O'Reilly, Inc\\\",\\\"Wall, Larry\\\",\\\"a \\\\\\\"glug\\\\\\\" bit,\\\",5,\\\"Error, Core Dumped,\\\",\""
]
}
],
"prompt_number": 140
},
{
"cell_type": "code",
"collapsed": false,
"input": [
"sio = IOBuffer(ezcsv)"
],
"language": "python",
"metadata": {},
"outputs": [
{
"metadata": {},
"output_type": "pyout",
"prompt_number": 141,
"text": [
"IOBuffer([0x61,0x2c,0x62,0x2c,0x63,0x0a,0x31,0x2c,0x32,0x2c,0x33,0x0a,0x34,0x2c,0x35,0x2c,0x36],true,false,true,false,17,9223372036854775807,1)"
]
}
],
"prompt_number": 141
},
{
"cell_type": "code",
"collapsed": false,
"input": [
"data_array =readdlm(sio, ',')"
],
"language": "python",
"metadata": {},
"outputs": [
{
"metadata": {},
"output_type": "pyout",
"prompt_number": 142,
"text": [
"3x3 Array{Any,2}:\n",
" \"a\" \"b\" \"c\"\n",
" 1.0 2.0 3.0 \n",
" 4.0 5.0 6.0 "
]
}
],
"prompt_number": 142
},
{
"cell_type": "code",
"collapsed": false,
"input": [
"close(sio)"
],
"language": "python",
"metadata": {},
"outputs": [],
"prompt_number": 143
},
{
"cell_type": "code",
"collapsed": false,
"input": [
"function stringdlm(source::String, delim::Char; has_header=false, use_mmap=false, ignore_invalid_chars=false)\n",
" \"\"\"parse a string of delimited text\"\"\"\n",
" sio = IOBuffer(source)\n",
" data_array =Base.readdlm(sio, ',')\n",
" close(sio)\n",
" return data_array\n",
"end "
],
"language": "python",
"metadata": {},
"outputs": [
{
"metadata": {},
"output_type": "pyout",
"prompt_number": 144,
"text": [
"stringdlm (generic function with 1 method)"
]
}
],
"prompt_number": 144
},
{
"cell_type": "code",
"collapsed": false,
"input": [
"stringdlm(ezcsv,',')"
],
"language": "python",
"metadata": {},
"outputs": [
{
"metadata": {},
"output_type": "pyout",
"prompt_number": 145,
"text": [
"3x3 Array{Any,2}:\n",
" \"a\" \"b\" \"c\"\n",
" 1.0 2.0 3.0 \n",
" 4.0 5.0 6.0 "
]
}
],
"prompt_number": 145
},
{
"cell_type": "markdown",
"metadata": {},
"source": [
"####readdlm() does not appear to know about quoted data, so it does not handle embedded delimiters well\n",
"\n",
"For example \"Wall, Larry\" should not have been split below."
]
},
{
"cell_type": "code",
"collapsed": false,
"input": [
"#bug in readdlm()?\n",
"for ln in stringdlm(line,',')'\n",
" println(ln)\n",
"end"
],
"language": "python",
"metadata": {},
"outputs": [
{
"output_type": "stream",
"stream": "stdout",
"text": [
"X"
]
},
{
"output_type": "stream",
"stream": "stdout",
"text": [
"YZZY\n",
"\"\"\n",
"\"O'Reilly\n",
" Inc\"\n",
"\"Wall\n",
" Larry\"\n",
"\"a \\\"glug\\\" bit\n",
"\"\n",
"5.0\n",
"\"Error\n",
" Core Dumped\n",
"\"\n"
]
}
],
"prompt_number": 146
},
{
"cell_type": "code",
"collapsed": false,
"input": [
"stringdlm(\"\"\"'Bush,Reggie','Morris,Alfred'\"\"\", ',')"
],
"language": "python",
"metadata": {},
"outputs": [
{
"metadata": {},
"output_type": "pyout",
"prompt_number": 147,
"text": [
"1x3 Array{Any,2}:\n",
" \"'Bush\" \"Reggie'\" \"'Morris\""
]
}
],
"prompt_number": 147
},
{
"cell_type": "markdown",
"metadata": {},
"source": [
"#### here are a couple of simple test files to demonstrate treatment of quoted data"
]
},
{
"cell_type": "markdown",
"metadata": {},
"source": [
"test0.csv:\n",
"\n",
" \"Name\",\"Age\",\"Weight\"\n",
" \"Bob\",26,160\n",
" \"Sue\",24,110"
]
},
{
"cell_type": "markdown",
"metadata": {},
"source": [
"test1.csv -- the name field includes embedded commas:\n",
"\n",
" \"Name\",\"Age\",\"Weight\"\n",
" \"Jones,Bob\",26,160\n",
" \"Collins,Sue\",24,110\n"
]
},
{
"cell_type": "markdown",
"metadata": {},
"source": [
"readdlm() does not seem to know about quotes around strings."
]
},
{
"cell_type": "code",
"collapsed": false,
"input": [
"readdlm(\"test0.csv\",',')"
],
"language": "python",
"metadata": {},
"outputs": [
{
"output_type": "stream",
"stream": "stdout",
"text": [
"\n"
]
},
{
"output_type": "stream",
"stream": "stderr",
"text": [
"WARNING: "
]
},
{
"output_type": "stream",
"stream": "stdout",
"text": [
"\n"
]
},
{
"ename": "LoadError",
"evalue": "new not defined\nat In[148]:1",
"output_type": "pyerr",
"traceback": [
"new not defined\nat In[148]:1",
" in mmap_array at mmap.jl:133"
]
}
],
"prompt_number": 148
},
{
"cell_type": "markdown",
"metadata": {},
"source": [
"as a consequence, readdlm() has trouble with test1.csv:"
]
},
{
"cell_type": "code",
"collapsed": false,
"input": [
"readdlm(\"test1.csv\",',')"
],
"language": "python",
"metadata": {},
"outputs": [
{
"output_type": "stream",
"stream": "stderr",
"text": [
"backtraces on your platform are often misleading or partially incorrect\n"
]
},
{
"ename": "LoadError",
"evalue": "new not defined\nat In[149]:1",
"output_type": "pyerr",
"traceback": [
"new not defined\nat In[149]:1",
" in mmap_array at mmap.jl:133"
]
}
],
"prompt_number": 149
},
{
"cell_type": "markdown",
"metadata": {},
"source": [
"####Package DataFrames contains as readtable() function that is smarter \n",
"However, it does not appear to have an option to using an IOBuffer at the moment."
]
},
{
"cell_type": "code",
"collapsed": false,
"input": [
"using DataFrames"
],
"language": "python",
"metadata": {},
"outputs": [
{
"output_type": "stream",
"stream": "stdout",
"text": [
"\n",
"\n"
]
}
],
"prompt_number": 150
},
{
"cell_type": "code",
"collapsed": false,
"input": [
"readtable(\"test0.csv\")"
],
"language": "python",
"metadata": {},
"outputs": [
{
"metadata": {},
"output_type": "pyout",
"prompt_number": 151,
"text": [
"2x3 DataFrame:\n",
" Name Age Weight\n",
"[1,] \"Bob\" 26 160\n",
"[2,] \"Sue\" 24 110\n"
]
}
],
"prompt_number": 151
},
{
"cell_type": "code",
"collapsed": false,
"input": [
"readtable(\"test1.csv\")"
],
"language": "python",
"metadata": {},
"outputs": [
{
"metadata": {},
"output_type": "pyout",
"prompt_number": 152,
"text": [
"2x3 DataFrame:\n",
" Name Age Weight\n",
"[1,] \"Jones,Bob\" 26 160\n",
"[2,] \"Collins,Sue\" 24 110\n"
]
}
],
"prompt_number": 152
},
{
"cell_type": "markdown",
"metadata": {},
"source": [
"##PLEAC 1.16-1.18 Soundex and Programs fixstyle, psgrep\n",
"Will not solve."
]
},
{
"cell_type": "code",
"collapsed": false,
"input": [
";ipython nbconvert 1_pleac_string.ipynb"
],
"language": "python",
"metadata": {},
"outputs": [
{
"output_type": "stream",
"stream": "stderr",
"text": [
"[NbConvertApp] Using existing profile dir: u'C:\\\\Users\\\\keithc\\\\.ipython\\\\profile_default'\r\n"
]
},
{
"output_type": "stream",
"stream": "stderr",
"text": [
"[NbConvertApp] Converting notebook 1_pleac_string.ipynb to html\r\n",
"[NbConvertApp] Support files will be in 1_pleac_string_files\\\r\n"
]
},
{
"output_type": "stream",
"stream": "stderr",
"text": [
"[NbConvertApp] Loaded template html_full.tpl\r\n"
]
},
{
"output_type": "stream",
"stream": "stderr",
"text": [
"[NbConvertApp] Writing 322023 bytes to 1_pleac_string.html\r\n"
]
}
],
"prompt_number": 157
},
{
"cell_type": "code",
"collapsed": false,
"input": [],
"language": "python",
"metadata": {},
"outputs": []
}
],
"metadata": {}
}
]
}