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   "source": [
    "# Conditionals"
   ]
  },
  {
   "cell_type": "markdown",
   "metadata": {},
   "source": [
    "## Testing truth value"
   ]
  },
  {
   "cell_type": "markdown",
   "metadata": {},
   "source": [
    "### `bool`"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": null,
   "metadata": {},
   "outputs": [],
   "source": [
    "print(f\"type of True and False: {type(True)}\")"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": null,
   "metadata": {},
   "outputs": [],
   "source": [
    "print(f\"0: {bool(0)}, 1: {bool(1)}\")\n",
    "print(f\"empty list: {bool([])}, list with values: {bool(['woop'])}\")\n",
    "print(f\"empty dict: {bool({})}, dict with values: {bool({'Python': 'cool'})}\")"
   ]
  },
  {
   "cell_type": "markdown",
   "metadata": {},
   "source": [
    "### `==, !=, >, <, >=, <=`"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": null,
   "metadata": {},
   "outputs": [],
   "source": [
    "print(f\"{1 == 0}\")\n",
    "print(f\"{1 != 0}\")\n",
    "print(f\"{1 > 0}\")\n",
    "print(f\"{1 > 1}\")\n",
    "print(f\"{1 < 0}\")\n",
    "print(f\"{1 < 1}\")\n",
    "print(f\"{1 >= 0}\")\n",
    "print(f\"{1 >= 1}\")\n",
    "print(f\"{1 <= 0}\")\n",
    "print(f\"{1 <= 1}\")"
   ]
  },
  {
   "cell_type": "markdown",
   "metadata": {},
   "source": [
    "You can combine these:"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": null,
   "metadata": {},
   "outputs": [],
   "source": [
    "print(f\"{1 <= 2 <= 3}\")"
   ]
  },
  {
   "cell_type": "markdown",
   "metadata": {},
   "source": [
    "### `and, or, not`"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": null,
   "metadata": {},
   "outputs": [],
   "source": [
    "python_is_cool = True\n",
    "java_is_cool = False\n",
    "empty_list = []\n",
    "secret_value = 3.14"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": null,
   "metadata": {},
   "outputs": [],
   "source": [
    "print(f\"Python and java are both cool: {python_is_cool and java_is_cool}\")\n",
    "print(f\"secret_value and python_is_cool: {secret_value and python_is_cool}\")"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": null,
   "metadata": {},
   "outputs": [],
   "source": [
    "print(f\"Python or java is cool: {python_is_cool or java_is_cool}\")\n",
    "print(f\"{1 >= 1.1 or 2 < 1.4}\")"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": null,
   "metadata": {},
   "outputs": [],
   "source": [
    "print(f\"Java is not cool: {not java_is_cool}\")"
   ]
  },
  {
   "cell_type": "markdown",
   "metadata": {},
   "source": [
    "You can combine multiple statements, execution order is from left to right. You can control the execution order by using brackets."
   ]
  },
  {
   "cell_type": "code",
   "execution_count": null,
   "metadata": {},
   "outputs": [],
   "source": [
    "print(bool(not java_is_cool or secret_value and python_is_cool or empty_list))\n",
    "print(bool(not (java_is_cool or secret_value and python_is_cool or empty_list)))"
   ]
  },
  {
   "cell_type": "markdown",
   "metadata": {},
   "source": [
    "## `if`"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": null,
   "metadata": {},
   "outputs": [],
   "source": [
    "statement = True\n",
    "if statement:\n",
    "    print(\"statement is True\")\n",
    "\n",
    "if not statement:\n",
    "    print(\"statement is not True\")"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": null,
   "metadata": {},
   "outputs": [],
   "source": [
    "empty_list = []\n",
    "# With if and elif, conversion to `bool` is implicit\n",
    "if empty_list:\n",
    "    print(\"empty list will not evaluate to True\")  # this won't be executed"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": null,
   "metadata": {},
   "outputs": [],
   "source": [
    "val = 3\n",
    "if 0 <= val < 1 or val == 3:\n",
    "    print(\"Value is positive and less than one or value is three\")"
   ]
  },
  {
   "cell_type": "markdown",
   "metadata": {},
   "source": [
    "## `if-else`"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": null,
   "metadata": {},
   "outputs": [],
   "source": [
    "my_dict = {}\n",
    "if my_dict:\n",
    "    print(\"there is something in my dict\")\n",
    "else:\n",
    "    print(\"my dict is empty :(\")"
   ]
  },
  {
   "cell_type": "markdown",
   "metadata": {},
   "source": [
    "## `if-elif-else`"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": null,
   "metadata": {},
   "outputs": [],
   "source": [
    "val = 88\n",
    "if val >= 100:\n",
    "    print(\"value is equal or greater than 100\")\n",
    "elif val > 10:\n",
    "    print(\"value is greater than 10 but less than 100\")\n",
    "else:\n",
    "    print(\"value is equal or less than 10\")"
   ]
  },
  {
   "cell_type": "markdown",
   "metadata": {},
   "source": [
    "You can have as many `elif` statements as you need. In addition, `else` at the end is not mandatory."
   ]
  },
  {
   "cell_type": "code",
   "execution_count": null,
   "metadata": {},
   "outputs": [],
   "source": [
    "greeting = \"Hello fellow Pythonista!\"\n",
    "language = \"Italian\"\n",
    "\n",
    "if language == \"Swedish\":\n",
    "    greeting = \"Hejsan!\"\n",
    "elif language == \"Finnish\":\n",
    "    greeting = \"Latua perkele!\"\n",
    "elif language == \"Spanish\":\n",
    "    greeting = \"Hola!\"\n",
    "elif language == \"German\":\n",
    "    greeting = \"Guten Tag!\"\n",
    "\n",
    "print(greeting)"
   ]
  },
  {
   "cell_type": "markdown",
   "metadata": {},
   "source": [
    "For more detailed overview about conditionals, check this [tutorial from Real Python](https://realpython.com/python-conditional-statements/)."
   ]
  }
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