CODEWITHSUNDEEP
pythonpandaslistcsvfor-loop
Chanda Steven
Chanda Steven

Reputation: 27

How to save a list of files names to CSV file in a FOR LOOP?

I have a CSV file with data (IDs) listed in one column and I added the extension to each ID via a for loop and then I would like to save the newly generated list in for loop to a CSV file. See the code. CSV file Data

import pandas as pd

# list of extension for the EEG images
channels = ['_Ch_01', '_Ch_02', '_Ch_03', '_Ch_04', '_Ch_05', '_Ch_06', '_Ch_07', '_Ch_08', 
'_Ch_09', '_Ch_10', '_Ch_11', '_Ch_12', '_Ch_13', '_Ch_14', '_Ch_15', '_Ch_16', '_Ch_17', 
'_Ch_18', '_Ch_19']

# Restrive the ID of images 
df = pd.read_csv ("Data.csv")

# Select the EDF column and add an extension to each ID
for ext in channels:
    png = df['Data'].tolist()
    png_list = list(map(lambda orig_string: orig_string + ext + ".png", png))
    for files in png_list:
        if files.endswith(".png"):
        print(files)
        print(f"want to save all the {files} to csv file in one column")

Thanks!

Upvotes: 1

Views: 789

Answers (1)

Code Different
Code Different

Reputation: 93181

You don't even need looping for this:

channels = [f"_Ch{i:02}.png" for i in range(1, 20)]

# Cross-product of df['Data'] and channels
# Essentially repeat each row in df['Data'] 19 times, once for each channel
index = pd.MultiIndex.from_product([df['Data'], channels])

# Concatenate the two levels of the index and export
s = index.get_level_values(0) + index.get_level_values(1)
s.to_series().to_csv('Output.csv', index=None, header=None)

Upvotes: 1

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