Custom csv output name with variable in loop in Python

Question

I have a code like this to process all files in folder and I've got a problem with last line. I want to save file after each iteration with custom name. Expample:

File in folder = SX.txt

Input value = 2

New file name = SX_2.txt

import glob
import pandas as pd
import os
    
txtfiles = []
for file in glob.glob("*.txt"):
    txtfiles.append(file)
print(txtfiles)

name_5=input("Mode number to extract:")

        
for filepath in glob.glob('*.txt'):
    with open(filepath) as file:
        #data1 = pd.DataFrame(pd.np.empty((0, 5))) 
        data1 = pd.read_csv(file, delim_whitespace=True , index_col=None, header=None)
        data1.columns  = ["a", "b", "c", "d","e"]

        data1['mode'] = data1.groupby(['b']).ngroup()
        data1['mode_1'] = data1['mode']+1
        data_d = data1[data1['mode_1'] == float(name_5)]
        del data_d["mode"]
        data_d["b"]=data_d["b"].round(decimals=3)
        data_d["c"]=data_d["c"].round(decimals=3)

        print(data_d)

        data_d.to_csv(f'{file} + "_" + {name_5}.csv', sep=' ', index=False)

Last line gives an error:

OSError: [Errno 22] Invalid argument: '<_io.TextIOWrapper name=\'SX1.txt\' mode=\'r\' encoding=\'cp1252\'> + "_" + 2.csv'

Could you help please? Thanks

and what is the problem ?

azro
– azro

2022-01-29 16:26:13 +00:00
Commented Jan 29, 2022 at 16:26 — azro
– azro, Commented Jan 29, 2022 at 16:26

azro · Accepted Answer · 2022-01-29 16:54:32Z

2

Problem

data_d.to_csv(f'{file} + "_" + {name_5}.csv', sep=' ', index=False)

You have confused what file is, that is a file descriptor openned on the original file,
you use a + in a f-string, that would string like 'SX + "_" + 5.csv'
if you want to keep extension, don't write .csv

Fix

data_d.to_csv(f'{filename[:-4]}_{name_5}.txt', sep=' ', index=False)

To simplify your comprehension : use file descriptor for both read and write OR none (pandas handles filename string)

txtfiles = glob.glob("*.txt")
print(txtfiles)
name_5 = input("Mode number to extract:")
for filename in txtfiles:
    data1 = pd.read_csv(filename, delim_whitespace=True, index_col=None, header=None)
    data1.columns = ["a", "b", "c", "d", "e"]
    data_d = data1[data1['mode_1'] == float(name_5)]
    # ...
    data_d.to_csv(f'{filename[:-4]}_{name_5}.csv', sep=' ', index=False)

edited Jan 29, 2022 at 16:54

answered Jan 29, 2022 at 16:29

azro

54.2k9 gold badges39 silver badges75 bronze badges

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

1 Comment

Paulina Over a year ago

Great, thank a lot!!! Now it's working! :)

Collectives™ on Stack Overflow

Custom csv output name with variable in loop in Python

1 Answer 1

Problem

Fix

1 Comment

Your Answer

Hot Network Questions

Collectives™ on Stack Overflow

1 Answer 1

Problem

Fix

1 Comment

Your Answer

Sign up or log in

Post as a guest

Related