Pandas Dataframe to_csv不会在Mac和Linux上附加（在Windows中会附加）

Question

I need to write a csv file with Pandas Dataframe appending csv rows.

I have written this piece of code that works fine in Windows. However, when I run it on our Linux Server or on Mac OSX it overwrites the file instead appending the next line.

 with open("Metrics-2SQUIDS.csv", "a+") as f:
    metrics_tosave.to_csv(f, columns=['C1', 'C2', 'C3'], sep=',', index=False)

I also tried with "a" instead of "a+". Both work fine with Windows but not in Mac or Linux. Is there any other test I can do?

Answer 1

You need mode optional argument to to_csv :

metrics_tosave.to_csv(f, mode='a', columns=['C1', 'C2', 'C3'], sep=',', index=False)

And I don't think you need with open() as f with this.