{
"cells": [
{
"cell_type": "markdown",
"id": "d240914c",
"metadata": {},
"source": [
"## Function Defination"
]
},
{
"cell_type": "markdown",
"id": "7a1d0d06",
"metadata": {},
"source": [
"- Positional arguments \n",
" - by default ones\n",
" - def foo(a,b)\n",
" - foo(2,3) # Here a and b are positional arguments and you need to pass both..If u miss even one,error will come\n",
" - means,the order in which we pass values when we call the function gets assigned its arguments respectively\n",
"- Keyword arguments\n",
" - you specify it explicitly using = symbol\n",
" - def foo(a,b='sahil')\n",
" - foo(2,3) # Here a is positional but b is keyword argument so is optional and you need to pass both..If u miss even one,error will come\n",
" \n",
"- Note: Keyword arguments should always be in the last during function declaration"
]
},
{
"cell_type": "markdown",
"id": "00b3f2ce",
"metadata": {},
"source": [
"### Make any argument as optional"
]
},
{
"cell_type": "code",
"execution_count": 12,
"id": "a7a03d7e",
"metadata": {},
"outputs": [],
"source": [
"def hi_random_person(name,age=None):\n",
" print('Hi',name)\n",
" if age:\n",
" print('I am '+ str(age)+' years old')"
]
},
{
"cell_type": "code",
"execution_count": 13,
"id": "e95a80f0",
"metadata": {},
"outputs": [
{
"name": "stdout",
"output_type": "stream",
"text": [
"Hi sahil\n"
]
}
],
"source": [
"hi_random_person('sahil')"
]
},
{
"cell_type": "code",
"execution_count": 14,
"id": "723795c8",
"metadata": {},
"outputs": [
{
"name": "stdout",
"output_type": "stream",
"text": [
"Hi sourav\n",
"I am 24 years old\n"
]
}
],
"source": [
"hi_random_person('sourav',24)"
]
},
{
"cell_type": "markdown",
"id": "4da6dcef",
"metadata": {},
"source": [
"### Set a default value for a argument"
]
},
{
"cell_type": "code",
"execution_count": 39,
"id": "498f7ee7",
"metadata": {},
"outputs": [],
"source": [
"def hi(name,place='Jammu'): # note: here name is called positional argument and place is called keyword argument\n",
" print('Hi ' + name+ \" from \"+ place)"
]
},
{
"cell_type": "code",
"execution_count": 28,
"id": "3de8ddb6",
"metadata": {},
"outputs": [
{
"name": "stdout",
"output_type": "stream",
"text": [
"Hi sahil from Jammu\n"
]
}
],
"source": [
"hi('sahil')"
]
},
{
"cell_type": "code",
"execution_count": 29,
"id": "68d1b1da",
"metadata": {},
"outputs": [
{
"name": "stdout",
"output_type": "stream",
"text": [
"Hi sourav from Mumbai\n"
]
}
],
"source": [
"hi('sourav','Mumbai')"
]
},
{
"cell_type": "markdown",
"id": "f19ab5d3",
"metadata": {},
"source": [
"#### Use case"
]
},
{
"cell_type": "code",
"execution_count": 48,
"id": "0cf41622",
"metadata": {},
"outputs": [
{
"name": "stdout",
"output_type": "stream",
"text": [
"3\n",
"3\n",
"1\n"
]
}
],
"source": [
"# Problem\n",
"def add(a,b):\n",
" return a+b\n",
"\n",
"print(add(1,2))\n",
"#print(add(1)) # it will throw error\n",
"\n",
"# Solution\n",
"def add(a,b=0): # or b=None\n",
" return a+b\n",
"\n",
"print(add(1,2))\n",
"print(add(1)) # it will throw error"
]
},
{
"cell_type": "markdown",
"id": "7de536a2",
"metadata": {},
"source": [
"### When you are unsure about the number of arguments - For positional arguments"
]
},
{
"cell_type": "markdown",
"id": "0ca1da7e",
"metadata": {},
"source": [
"- Use single asterick\n",
"- *args\n",
"- Note: it picks all the arguments after the positional arguments are assigned\n",
"- args is tupple by default"
]
},
{
"cell_type": "code",
"execution_count": 59,
"id": "7aafcf1c",
"metadata": {},
"outputs": [],
"source": [
"def hi(*arguments): \n",
" return 'hi'+ str(arguments)"
]
},
{
"cell_type": "code",
"execution_count": 60,
"id": "11abcb2a",
"metadata": {},
"outputs": [
{
"name": "stdout",
"output_type": "stream",
"text": [
"hi('sahil',)\n",
"hi('sahil', 'sourav')\n"
]
}
],
"source": [
"print(hi('sahil'))\n",
"print(hi('sahil','sourav'))"
]
},
{
"cell_type": "markdown",
"id": "d823662c",
"metadata": {},
"source": [
"### When you are unsure about the number of arguments and you don't want to assign arguments in advance - For keyword arguments"
]
},
{
"cell_type": "markdown",
"id": "a970ac32",
"metadata": {},
"source": [
"- Use double asterick\n",
"- **kwargs\n",
"- **kwargs is dictinary by default\n",
"- Note: kwargs (or **) only picks up the = arguments\n",
"- common usecase is when u wrote one function for superclass and in subclasses you need only few arguments"
]
},
{
"cell_type": "code",
"execution_count": 62,
"id": "065a50d3",
"metadata": {},
"outputs": [],
"source": [
"def hi(**arguments):\n",
" return 'hi'+ str(arguments)"
]
},
{
"cell_type": "code",
"execution_count": 64,
"id": "fead4b03",
"metadata": {},
"outputs": [
{
"ename": "TypeError",
"evalue": "hi() takes 0 positional arguments but 1 was given",
"output_type": "error",
"traceback": [
"\u001b[1;31m---------------------------------------------------------------------------\u001b[0m",
"\u001b[1;31mTypeError\u001b[0m Traceback (most recent call last)",
"\u001b[1;32m<ipython-input-64-25353f36f7a9>\u001b[0m in \u001b[0;36m<module>\u001b[1;34m\u001b[0m\n\u001b[1;32m----> 1\u001b[1;33m \u001b[0mprint\u001b[0m\u001b[1;33m(\u001b[0m\u001b[0mhi\u001b[0m\u001b[1;33m(\u001b[0m\u001b[1;34m'sahil'\u001b[0m\u001b[1;33m)\u001b[0m\u001b[1;33m)\u001b[0m \u001b[1;31m# it will give error :hi() takes 0 positional arguments but 1 was given because\u001b[0m\u001b[1;33m\u001b[0m\u001b[1;33m\u001b[0m\u001b[0m\n\u001b[0m\u001b[0;32m 2\u001b[0m \u001b[1;31m# kwargs (or **) only picks the values passed as =\u001b[0m\u001b[1;33m\u001b[0m\u001b[1;33m\u001b[0m\u001b[1;33m\u001b[0m\u001b[0m\n",
"\u001b[1;31mTypeError\u001b[0m: hi() takes 0 positional arguments but 1 was given"
]
}
],
"source": [
"print(hi('sahil')) # it will give error :hi() takes 0 positional arguments but 1 was given because\n",
"# kwargs (or **) only picks the values passed as ="
]
},
{
"cell_type": "code",
"execution_count": 65,
"id": "ec03a350",
"metadata": {},
"outputs": [
{
"name": "stdout",
"output_type": "stream",
"text": [
"hi{'name': 'sahil'}\n"
]
}
],
"source": [
"print(hi(name='sahil'))"
]
},
{
"cell_type": "code",
"execution_count": 67,
"id": "e3dc38bc",
"metadata": {},
"outputs": [
{
"name": "stdout",
"output_type": "stream",
"text": [
"hi{'name1': 'sahil', 'name2': 'sourav'}\n"
]
}
],
"source": [
"print(hi(name1='sahil',name2='sourav'))"
]
},
{
"cell_type": "markdown",
"id": "dd6011bb",
"metadata": {},
"source": [
"### Summary (All used in one Example)"
]
},
{
"cell_type": "code",
"execution_count": 75,
"id": "e7ac7025",
"metadata": {},
"outputs": [],
"source": [
"def hi(a,b,*args,**kwargs):\n",
" return 'hi '+str(a)+ str(b)+ str(args)+ str(kwargs)"
]
},
{
"cell_type": "code",
"execution_count": 76,
"id": "0b5c8c85",
"metadata": {},
"outputs": [
{
"data": {
"text/plain": [
"'hi 1020(){}'"
]
},
"execution_count": 76,
"metadata": {},
"output_type": "execute_result"
}
],
"source": [
"hi(10,20) # both these will be picked by positional arguments (a,b) only \n",
"# also,if you even miss one value and pass only one value,it will throw error.\n",
"# all the positional arguments must be passed always.This is the rule"
]
},
{
"cell_type": "code",
"execution_count": 77,
"id": "c4d7adc4",
"metadata": {},
"outputs": [
{
"data": {
"text/plain": [
"'hi 1020(30, 40){}'"
]
},
"execution_count": 77,
"metadata": {},
"output_type": "execute_result"
}
],
"source": [
"hi(10,20,30,40) # after taking and b from arguments,rest everything will be taken as args\n",
"# and since args comes as tupple by default,they will be in tupple"
]
},
{
"cell_type": "code",
"execution_count": 78,
"id": "f784224e",
"metadata": {},
"outputs": [
{
"data": {
"text/plain": [
"'hi 1020(30, 40, 50, 60){}'"
]
},
"execution_count": 78,
"metadata": {},
"output_type": "execute_result"
}
],
"source": [
"hi(10,20,30,40,50,60) # after taking and b from arguments,rest everything will be taken as args\n",
"# and since args comes as tupple by default,they will be in tupple\n",
"# Note: No kwargs will be taken because nothing is passed as ="
]
},
{
"cell_type": "code",
"execution_count": 80,
"id": "abef001f",
"metadata": {},
"outputs": [
{
"data": {
"text/plain": [
"\"hi 1020(30, 40, 50, 60){'x': 70, 'y': 80}\""
]
},
"execution_count": 80,
"metadata": {},
"output_type": "execute_result"
}
],
"source": [
"hi(10,20,30,40,50,60,x=70,y=80) # x and y will be taken as kwars since they value =\n",
"# and kwargs comes as dictionary by default"
]
}
],
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"display_name": "Python 3",
"language": "python",
"name": "python3"
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"codemirror_mode": {
"name": "ipython",
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"file_extension": ".py",
"mimetype": "text/x-python",
"name": "python",
"nbconvert_exporter": "python",
"pygments_lexer": "ipython3",
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