python none code example

Example 1: python 2.7 check if variable is none

>>> NoneType = type(None)
>>> x = None
>>> type(x) == NoneType
True
>>> isinstance(x, NoneType)
True

Example 2: pythonhow to check if value is None

# How to check if a variable is None

var = None
# variable is None in this example

if var is None:
  # if var is None
  
  print("var is None")
  # code...
  
else:
  # if var is not None
  
  print("var is not None")
  # code...

# result of above example "var is None"



var = "sometext"
# variable is not None in this example

if var is None:
  # if var is None
  
  print("var is None")
  # code...
  
else:
  # if var is not None
  
  print("var is not None")
  # code...

# result of above example "var is not None"

Example 3: None python

# The None keyword is effectively the same as null
# Functions without a return will return None

>>> def has_no_return():
...     pass
>>> has_no_return()
>>> print(has_no_return())
None

# Often, you’ll use None as part of a comparison.
# One example is when you need to check and see if some result or parameter is None.

>>> import re
>>> match = re.match(r"Goodbye", "Hello, World!")
>>> if match is None:
...     print("It doesn't match.")
"It doesn't match."