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"source": [
"## Exercise 2"
]
},
{
"cell_type": "markdown",
"metadata": {},
"source": [
"**a)** Take a few minutes to browse the modules in the [Python module index](https://docs.python.org/3/py-modindex.html)."
]
},
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"cell_type": "markdown",
"metadata": {},
"source": [
"**b)** Import the module `datetime`, a module that provides functionality for working with dates. We will now use it to calculate your age in days, hours and seconds repsectively.\n",
"\n",
"Write a function that accepts a birth date of a person:\n",
"\n",
"`> calculate_age(1999, 1, 2, hour=12, minute=2, second=33)`\n",
"```\n",
"You are 7263 days old\n",
"You are 174313 hours old\n",
"You are 627527127 seconds old\n",
"```\n",
"\n",
"\n",
"Year, month and date is required, the other values are optional. The default values of hour, minute and second should be 0.\n",
"\n",
"The function should print the following:\n",
"\n",
"- How many days is the person?\n",
"- How many hours is the person?\n",
"- How many seconds is the person?\n",
"\n",
"The `datetime` module will provide you with the number of days and seconds. You will need to calculate the number of hours on your own.\n",
"\n",
"**Hints:**\n",
"- Use the [`datetime Object`](https://docs.python.org/3/library/datetime.html#datetime-objects) to solve the exercise.\n",
"\n",
"- Find out how to make a `datetime` object representing the current time.\n",
"\n",
"- Find out how to make a `datetime` object representing a given date and time (the birth date). \n",
"\n",
"- Look at the supported operations for this type to find how you can get the difference between two objects of type `datetime`.\n",
"\n",
"- You will get difference represented as an object (a [`timedelta`](https://docs.python.org/3/library/datetime.html#timedelta-objects)).\n",
"\n",
"- Use `.days` and `.total_seconds()` to get the number of days and seconds."
]
},
{
"cell_type": "markdown",
"metadata": {},
"source": [
"**c)** Test your functions by giving it different input and make sure that they give the expected output."
]
},
{
"cell_type": "markdown",
"metadata": {},
"source": [
"### Bonus exercises"
]
},
{
"cell_type": "markdown",
"metadata": {},
"source": [
"**d)** Go back to the previous IMDB exercise, where you defined the `pick_movie()` function.\n",
"\n",
"Use the module `random` to make the movie picker less predictable: instead of always returning the first matching movie from the file, return a randomly picked movie (which still matches the user's criteria)."
]
},
{
"cell_type": "markdown",
"metadata": {},
"source": [
"\n",
"-----\n",
"
\n",
"
\n",
"
\n",
"Proposed solution
\n",
"\n",
"
"
]
},
{
"cell_type": "markdown",
"metadata": {},
"source": [
"#### Proposed solution for b)"
]
},
{
"cell_type": "code",
"execution_count": 3,
"metadata": {},
"outputs": [],
"source": [
"import datetime\n",
"\n",
"def calculate_age(year, month, day, hour=0, minute=0, second=0):\n",
" \"\"\" Calculate the number of days, hours and seconds that have passed since a given date \"\"\"\n",
" # create a date object for current time\n",
" now = datetime.datetime.now()\n",
" # create a date object for the giventime\n",
" born = datetime.datetime(year, month, day, hour, minute, second)\n",
" # compare them\n",
" diff = now - born\n",
" # get the number of days that have passed\n",
" days = diff.days\n",
" # get the number of seconds\n",
" tot_seconds = int(diff.total_seconds())\n",
" # convert into hours using floor division\n",
" hours = tot_seconds // 3600\n",
" print('You are ' + str(days) + ' days old')\n",
" print('You are ' + str(hours) + ' hours old')\n",
" print('You are ' + str(tot_seconds) + ' seconds old')"
]
},
{
"cell_type": "code",
"execution_count": 4,
"metadata": {},
"outputs": [
{
"name": "stdout",
"output_type": "stream",
"text": [
"You are 12650 days old\n",
"You are 303615 hours old\n",
"You are 1093014139 seconds old\n"
]
}
],
"source": [
"calculate_age(1984, 3, 19)"
]
},
{
"cell_type": "markdown",
"metadata": {},
"source": [
"#### Proposed solution for the bonus exercise"
]
},
{
"cell_type": "code",
"execution_count": 5,
"metadata": {},
"outputs": [],
"source": [
"import random\n",
"\n",
"imdb = \"../../downloads/250.imdb\"\n",
"\n",
"def pick_movie_b_ii(year=None, genre=None, rating_min=None, rating_max=None):\n",
" # read all lines and keep them in memory\n",
" lines = open(imdb).readlines()\n",
" # use random to shuffle the lines (put them in random order)\n",
" random.shuffle(lines)\n",
" # now go through the lines and return the first one that fits\n",
" for line in lines:\n",
" if line.startswith('#'):\n",
" continue\n",
" fields = line.split('|')\n",
" # Remeber to type cast to float\n",
" rating = float(fields[1].strip())\n",
" title = fields[-1].strip()\n",
" m_year = fields[2].strip()\n",
" genres = fields[-2].strip().split(',')\n",
" # Go through criterias\n",
" ok_year = not year or m_year == year\n",
" ok_genre = not genre or genre in genres\n",
" ok_min = not rating_min or rating_min <= rating\n",
" ok_max = not rating_max or rating_max >= rating\n",
" if ok_year and ok_genre and ok_min and ok_max:\n",
" # All criterias ok, print the movie and break the loop\n",
" print(title)\n",
" break\n"
]
},
{
"cell_type": "code",
"execution_count": 6,
"metadata": {},
"outputs": [
{
"name": "stdout",
"output_type": "stream",
"text": [
"A Beautiful Mind\n"
]
}
],
"source": [
"pick_movie_b_ii(year=\"2001\")"
]
},
{
"cell_type": "code",
"execution_count": 7,
"metadata": {},
"outputs": [
{
"name": "stdout",
"output_type": "stream",
"text": [
"Spirited Away\n"
]
}
],
"source": [
"pick_movie_b_ii(year=\"2001\")"
]
}
],
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