all Python 3deprecated in 3.15osfunction

os.path.commonprefix

os.path — path parsing

Return the longest common prefix of a list of strings — character-wise, not path-aware.

Syntax

os.path.commonprefix(list)

It compares characters, not components, so for paths it gives a wrong answer: commonprefix(['/usr/lib', '/usr/local']) returns '/usr/l' — no such directory. Use commonpath for paths. The function itself is fine for any strings, e.g. finding the shared start of a word list. Since Python 3.15 the function is deprecated and emits a DeprecationWarning: for paths use commonpath(), for the shared start of strings compare characters, e.g. with zip and itertools.takewhile.

Examples

import os
print(os.path.commonprefix(['abcd', 'abef']))   # → ab
print(os.path.commonprefix(['flower', 'flow', 'flight']))   # → fl
print(os.path.commonprefix(['/usr/lib', '/usr/lib64']))   # → /usr/lib
print(os.path.commonpath(['/usr/lib', '/usr/lib64']).endswith('usr'))   # → True
print(repr(os.path.commonprefix([])))   # → ''

os.path.commonprefix

Syntax

Examples

See also