Python None

Python None

None is a special constant in Python that represents the absence of a value.

Its data type is NoneType, and None is the only instance of a NoneType object.

NoneType

Variables can be assigned None to indicate "no value" or "not set".

Example

x = None
print(x)

Use type() to see the type of a None value.

Example

x = None
print(type(x))

Comparing to None

To compare a value to None, use the identity operator is or is not

Example

result = None
if result is None:
  print("No result yet")
else:
  print("Result is ready")

Example

result = None
if result is not None:
  print("Result is ready")
else:
  print("No result yet")

True or False

None evaluates to False in a boolean context.

Example

print(bool(None))

Functions returning None

Functions that do not explicitly return a value return None by default.

Example

def myfunc():
  x = 5

x = myfunc()
print(x)