import os, glob, time, operator
def get_oldest_file(files, _invert=False):
""" Find and return the oldest file of input file names.
Only one wins tie. Values based on time distance from present.
Use of `_invert` inverts logic to make this a youngest routine,
to be used more clearly via `get_youngest_file`.
"""
gt = operator.lt if _invert else operator.gt
# Check for empty list.
if not files:
return None
# Raw epoch distance.
now = time.time()
# Select first as arbitrary sentinel file, storing name and age.
oldest = files[0], now - os.path.getctime(files[0])
# Iterate over all remaining files.
for f in files[1:]:
age = now - os.path.getctime(f)
if gt(age, oldest[1]):
# Set new oldest.
oldest = f, age
# Return just the name of oldest file.
return oldest[0]
def get_youngest_file(files):
return get_oldest_file(files, _invert=True)
# Example.
files = glob.glob('*.py')
print 'oldest:', get_oldest_file(files)
print 'youngest:', get_youngest_file(files)
