TypeError: expected string or bytes-like object for Regex in Python

Question

I am trying to search some files through regular expression, my target files look like: 'Myfile_200_2018.csv';'Myfile_100_2018.csv'....

For example, the following code keeps give the error: expected string or bytes-like object for Regex in Python.

I searched same error from Google, but I think my game_id is a string right? So I am not sure which part causes the error.

import os
import re

allfiles = os.listdir('.')

csv_files = [filename for filename in allfiles if filename.endswith('.csv')]


game_id='100'

re.search(r'(Myfile_%s_\d{4}.csv$)'%game_id, csv_files)

But in this folder there are several csv files, the csv_files contains list of csv files, and when the game_id='100", just want to return all csv files match the format, it yams contains:'Myfile_100_2018.csv', 'Myfile_100_2017.csv','Myfile_100_2016.csv' — Rowling
– Rowling, Commented Nov 29, 2018 at 3:55
That's not how re.search works. Use a different method; you can't look up a function, plug in whatever arguments you think will work, and expect it to do so. — iz_
– iz_, Commented Nov 29, 2018 at 4:02
You are already looping through the list of files. Why don't you filter it there at the time when you create the list? like csv_files = [filename for filename in allfiles if filename.endswith('.csv') and re.search((r"Myfile_%s_\d{4}.csv$" % game_id), filename)] ? — Nimeshka Srimal
– Nimeshka Srimal, Commented Nov 29, 2018 at 4:29

Nimeshka Srimal · Accepted Answer · 2018-11-29 04:39:16Z

2

You are already looping through the files in your folder. Why not filter the list when you create it?

import os
import re

allfiles = os.listdir('.')
game_id='100'

csv_files = [
                filename for filename in allfiles if filename.endswith('.csv') and 
                re.search((r"Myfile_%s_\d{4}.csv$" % game_id), filename)
            ]

print csv_files

Or if you want to keep the original list as well, you could use filter to create a new filtered list.

csv_files = [filename for filename in allfiles if filename.endswith('.csv')]

filtered_list = filter(lambda filename: re.search((r"Myfile_%s_\d{4}.csv$" % game_id), filename), csv_files)

edited Nov 29, 2018 at 4:39

answered Nov 29, 2018 at 4:31

Nimeshka Srimal

9,1605 gold badges48 silver badges62 bronze badges

Sign up to request clarification or add additional context in comments.

Comments

Venkatachalam · Accepted Answer · 2018-11-29 05:15:15Z

1

You can use the substring search in your list, if you just want to seach whether the game_id is present in the filename or not

import os
import re

allfiles=['Myfile_100_2018.csv', 'Myfile_100_2017.csv','Yourfile_100_2016.csv','Myfile_200_2018.csv','Myfile_100_2018.csv']

csv_files = [filename for filename in allfiles if filename.endswith('.csv')]


game_id='100'

print([file for file in csv_files if re.search((r"Myfile_%s_\d{4}.csv$" % game_id),file)])

output:

['Myfile_100_2018.csv', 'Myfile_100_2017.csv', 'Myfile_100_2018.csv']

edited Nov 29, 2018 at 5:15

answered Nov 29, 2018 at 3:54

Venkatachalam

17k10 gold badges52 silver badges78 bronze badges

5 Comments

Rowling Over a year ago

But i want to return a list which match the regex, since in this folder there are several csv files, the csv_files contains list of csv files, and when the game_id='100", just want to return all csv files match the format, it yams contains:'Myfile_100_2018.csv', 'Myfile_100_2017.csv','Myfile_100_2016.csv'

Venkatachalam Over a year ago

I have changed the code to return the files instead of bool values

iz_ Over a year ago

I doubt OP wants the zeros in the list, so use [file for file in csv_files if game_id in file] instead.

Rowling Over a year ago

How about if there is a file calls 'Yourfile_100_2018.csv, it will still return as a result

Venkatachalam Over a year ago

Then what is your condition to choose your file apart from game id

Collectives™ on Stack Overflow

TypeError: expected string or bytes-like object for Regex in Python

2 Answers 2

Comments

5 Comments

Your Answer

Hot Network Questions

Collectives™ on Stack Overflow

2 Answers 2

Comments

5 Comments

Your Answer

Sign up or log in

Post as a guest

Related