How to code python with pep standard

Pep8 standards are coding convention which help to write python code. The purpose of Pep8 to write a code in such a way it is easily understand for other. The following are the main pep8 standard points.

Variable naming conventions should any one following.

underscore_case
```
my_name =  "Muhammad Faizan"
```
snakeCase
```
myName = "Muhammad Faizan"
```
PascalCase
```
MyName = "Muhammad Faizan"
```

Constant variable names should name all the capital letter.
```
MY_NAME = "Muhammad Faizan"
```
Name of the user-defined function name should be underscore case.
```
def hello_greet():
return "hello"
```
Class name should be start from capital character
- 'self' should be first name in class function.
```
class Person:
```
import all libraries should be on top and if you import something from same module in single line is OK. Avoid to use asterik to import all the things from file.
- Correct
```
from calculation import add, sub, mul
```
- Wrong
```
from calculation import *
```
Don't use unnecessary white spaces.
Don't use white spaces in default parameter of user-defined function.

Inline comment should be following

Correct:

user_name = 'muhammad_faizan'  # name of user

Wrong:

user_name = 'muhammad_faizan' #name of user

Validating the variable.

Correct:
```
x = None
if x is None:
  pass
```

incorrect:
```
if x:
   pass
```
Wrong:
```
if x == None:
   pass
```

Checking the desired character in variable.

Correct

user_name = 'muh_faizan'  # name of user 
if user_name.startswith('muh'):
  print("correct")

Correct

if user_name.endswith('faizan'):
  print("correct")

Wrong:

if username[:3] == 'muh':
  print("correct")

Reference: peps.python.org/pep-0008/#whitespace-in-exp..

Python PEP 8 standard