Multiple pandas.dataframe to one csv file

问题

I have multiple pandas dataframes, and hope to write them as one CSV file. What is the most straightforward way?

For example, from following four dataframes,

how can I create below CSV?

Note The dataframes all have the same dimensions.

回答1:

A very straightforward way would be to concat pairs horizontally, concat the results vertically, and write it all out using to_csv:

 import pandas as pd

 pd.concat([
    pd.concat([df1, df2], axis=1),
    pd.concat([df3, df4], axis=1)]).to_csv('foo.csv')

---

A possibly more memory-conserving way would be to write it piecemeal:

with open('foo.csv', 'w') as f:
     pd.concat([df1, df2], axis=1).to_csv(f)
with open('foo.csv', 'a') as f:
     pd.concat([df3, df4], axis=1).to_csv(f, header=False)

Omitting headers=False would repeat the headers.

来源：https://stackoverflow.com/questions/30829748/multiple-pandas-dataframe-to-one-csv-file