CODEWITHSUNDEEP
python
Yumna
Yumna

Reputation: 35

How do I add an if and else statement to python?

I'm currently learning python and I'm trying to add if/else statements.

For example, I have this script that changes the file names within a directory to something else: 

import os

#changes directory
os.chdir('/home/Documents/agreements')

for f in os.listdir('/home/rachellegarcia/Documents/agreements'):
    f_name, f_ext = os.path.splitext(f)
    f_patient, f_conf, f_agmt, f_email = f_name.split('_')
    f_agmt_type, f_agmt_staff = f_agmt.split('-')

    #sets the new name
    new_name = '{}-{}{}'.format(f_agmt_staff, f_email, f_ext)

    #renames the file
    os.rename(f, new_name.replace('-', '@'))

What I would like is if a new file gets added to the directory, then it'll change it too.

But I think because don't have an if/else statement I get an error: 

File "/home/Documents/python/renamefiles.py", line 8, in <module>
  f_patient, f_conf, f_agmt, f_email = f_name.split('_')
ValueError: need more than 1 value to unpack

So, I wanted to know if I can add something like;

if the new_name is set, then skip and continue the loop.

Thanks for the help! :)

Upvotes: 0

Views: 56

Answers (1)

donkopotamus
donkopotamus

Reputation: 23176

Your error is occurring because it is encountering a file that does not fit the format you expect ... of four parts separated by _.

You could cope with this by using a try ... except ... around the line in question and continue-ing the loop if it does not fit that format. 

for f in os.listdir('/home/rachellegarcia/Documents/agreements'):
    f_name, f_ext = os.path.splitext(f)

    try:
        f_patient, f_conf, f_agmt, f_email = f_name.split('_')
    except ValueError:
        # ... it wasn't the format expected, skip it
        continue

    # ... it was the format expected
    f_agmt_type, f_agmt_staff = f_agmt.split('-')

    #sets the new name
    new_name = '{}-{}{}'.format(f_agmt_staff, f_email, f_ext)

    #renames the file
    os.rename(f, new_name.replace('-', '@'))

In the long run it may be more robust to check each filename against a regular expression that describes the exact format you expect.

Upvotes: 1

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