def myfunc(a,b,c=0):
return sum((a,b,c))*0.05
>>myfunc(10,20)
>>1.5
>>myfunc(10,20,30,40) #will give you an error 3 param but take 4 parama
*args args
>>> number =[1,2,3,4,5]
>>> number
[1, 2, 3, 4, 5]
>>> print(*number)
1 2 3 4 5
>>> print(*'abc')
a b c
>> def myfunc(*args): #*args return tuple of parameter
return sum(args)*0.05
>> myfunc(10,20,30,40) #here you can pass n number of parameter
**kwargs
>> def myfunc(**kwargs):
print(kwargs)
if 'fruit' in kwargs:
print('My fruit is {}'.format(kwargs['fruit']))
else:
print("No fruit nor vege")
>> myfunc(fruit='apple',vege='tomatto',nice='hi')
**output
{'fruit': 'apple', 'vege': 'tomatto', 'nice': 'hi'}
My fruit is apple
>> class Dog():
def __init__(self,breed):
self.breed=breed
def __str__(self):
return f"{self.breed}"
>> a=Dog('Desi')
>> a
<__main__.Dog object at 0x000002CB881757E0>
>> print(a)
Desi
Some more code related to class
>> class Dog():
def __init__(self,author,num):
self.author=author
self.num=num
def __str__(self):
return f"{self.author}"
def __len__(self):
return self.num
def __del__(self):
print("Something deleted")
>> b=Dog('PK',20)
>> b
<__main__.Dog object at 0x000002CB88174310>
>> print(b)
PK
>> print(len(b))
20
>> del b
b
Why decorator
### In this code we can call hello function but can't directly call greet and welcome so we go for decorator
>> def hello():
print("hello")
def greet():
return "\t greet"
def welcome():
return '\t\t Welcome'
print(greet())
print(welcome())
>> hello()
hello
greet
Welcome
Decorator
>> def original_func():
print('hello')
>> def new_decorator(orignal_func):
def wrap_func():
print("Some extra code")
original_func()
print('Some more extra code')
return wrap_func()
>> decorated_func=new_decorator(func_need_decorator)
Some extra code
hello
Some more extra code
>> @new_decorator
def func_need_decorator():
print("Decorated")
Some extra code
hello
Some more extra code
Without generator
>> def without_gen(n):
result=[]
for i in range(n):
result.append(i**3)
return result
>> without_gen(10)
[0, 1, 8, 27, 64, 125, 216, 343, 512, 729]
With Generator
>> def generator(n):
for i in range(n):
yield i**3
>> for i in generator(10):
print(i)
0
1
8
27
64
125
216
343
512
729
Fibonacci number
>> def fibo(n):
a=1
b=1
for i in range(n):
yield a
a,b=b,a+b
>> for i in fibo(10):
print(i)
1
1
2
3
5
8
13
21
34
55
Simple generator
>> def gen(n):
for i in range(n):
yield i
>> for i in gen(10):
print(i)
Another use of generator
>> def gen():
for i in range(3):
yield i
>> g=gen()
>> g.__next__()
0
>> g.__next__()
1
>> g.__next__()
2
>> g.__next__()
>> string="hello world 123 456"
>> pattern="123"
>> import re
>> re.search(pattern,string)
<re.Match object; span=(12, 15), match='123'>
>> match=re.search(pattern,string)
>> match.span()
(12, 15)
>> match.start()
12
>> match.end()
15
>> string="hello world 123 456 123"
>> re.findall(pattern,string)
['123', '123']
>> match=re.search(pattern,string)
>> for match in re.finditer(pattern,string):
print(match)
<re.Match object; span=(12, 15), match='123'>
<re.Match object; span=(20, 23), match='123'>
Some more about re
>> import re
>> text="My phone number is 405-555-7777"
>> phone=re.search(r'\d\d\d-\d\d\d-\d\d\d\d',text)
>> phone
<re.Match object; span=(19, 31), match='405-555-7777'>
>> phone.group()
'405-555-7777'
>> # using quantifiers
>> phone=re.search(r'\d{3}-\d{3}-\d{4}',text)
>> phone
<re.Match object; span=(19, 31), match='405-555-7777'>
>> phone_pattern=re.compile(r'(\d{3})-(\d{3})-(\d{4}))
### Compile run the multiple search at once
>> phone_pattern=re.compile(r'(\d{3})-(\d{3})-(\d{4})')
>> result=re.search(phone_pattern,text)
>> result.group()
'405-555-7777'
>> result.group(1)
'405'
### Operator Or(|), wildcard(.),
>> string="Hello dog it's me"
>> re.search(r'cat|dog',string) #| this is or symbol
<re.Match object; span=(6, 9), match='dog'>
>> re.search(r'.e',string) #.e is a wildcard similar to like (_) operator can use multiple for multiple single char
<re.Match object; span=(0, 2), match='He'>
>> string="Hello 1 dog it's me"
>> re.findall(r'^\d',string) #^\d it's mean the string start with number
[]
>> string="1 Hello dog it's me"
>> re.findall(r'^\d',string) #^\d it's mean the string start with number
['1']
>> string="Number ends with 2"
>> re.findall(r'\d$',string) #^\$ it means number at last
['2']
>> string= "there are 3 number 35 inside this sentence"
>> pattern=r'[^\d]' # to exclude numbers
>> re.findall(pattern,string)
['t', 'h', 'e', 'r', 'e', ' ', 'a', 'r', 'e', ' ', ' ', 'n', 'u', 'm', 'b', 'e', 'r', ' ', ' ', 'i', 'n', 's', 'i', 'd', 'e', ' ', 't', 'h', 'i', 's', ' ', 's', 'e', 'n', 't', 'e', 'n', 'c', 'e']
>> ''.join(re.findall(pattern,string))
'there are number inside this sentence'
>> pattern=r'[^\d]+' #
>> re.findall(pattern,string)
['there are ', ' number ', ' inside this sentence']
>> string="This is, punctuation. marks?"
>> re.findall(r'[^!,.?]+',string) #it remove all punctuation marks
['This is', ' punctuation', ' marks']
>> string="only find hyphen-word in this-sentence"
>> re.findall(r'[\w]+-[\w]+',string)
['hyphen-word', 'this-sentence']
How to remove data using pop and store it in third variable
