Check if a list is empty in Python
October 25, 2020 ‐ 1 min read
Testing whether a list is empty is quite straightforward in Python. In the context of a if or while statement an empty list will be evaluated as False. Like how empty strings or empty dicts are evaluated as False as well.
glass = []
if not glass:
print('Glass is empty')
# => Glass is empty
The PEP8 style guide prefers the option as shown above. But in case you rather do a more explicit check the following will do. By comparing with [] we know for sure that glass is a list.
glass = []
if glass == []:
print('Glass is empty')
# => Glass is empty
Another option is using the len() function in case you rather be somewhat explicit. This way we validate that glass is at least a sequence(str, list, tuple, ...).
glass = []
if len(glass) == 0:
print('Glass is empty')
# => Glass is empty