CODEWITHSUNDEEP
regexdatetimepython-2.7
More Than Five
More Than Five

Reputation: 10419

Ensure filename is in datetime correct format

I want all my files to be off format: 2013-03-31_142436.jpg i.e. %Y-%m-%d_%H%M%S

I have a script to rename that way but would like to check if the filename is of the format first. I do:

for filename in files:
    # check filename not already in file format
    filename_without_ext = os.path.splitext(filename)[0];

How do I check filename_without_ext is of format %Y-%m-%d_%H%M%S

Upvotes: 0

Views: 192

Answers (2)

Martijn Pieters
Martijn Pieters

Reputation: 1121942

Just try to parse it as a timestamp:

from time import strptime

try:
    strptime(filename_without_ext, '%Y-%m-%d_%H%M%S')
except ValueError:
    # Not a valid timestamp

The strptime() test has the advantage that it guarantees that you have a valid datetime value, not just a pattern of digits that still could represent an invalid datetime ('1234-56-78_987654' is not a valid timestamp, for example).

Upvotes: 2

Jon Clements
Jon Clements

Reputation: 142156

Use re:

import re
if re.match(r'\d{4}-\d{2}-\d{2}_\d{6}$', filename_without_ext):
    pass # of the right format

This will just check it looks like it has a chance of being a valid date. Use Martijn's answer if you require it to be a valid date.

Upvotes: 2

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