Python write 2 lists and Pandas DataFrames to csv/excel sequentially

Question

I have these Python lists and Pandas Dataframes:

list_1 = ['Intro line here - record of method function:']
list_2 = ['Record of local minimum follows:']

print df_1
   Col_A    Col_B
  3.4443    1.443
 10.8876    11.99

print df2
Trial_1  Trial_2  Trial_3
    1.1     1.49    775.9
   11.5     9.57     87.3
 384.61   77.964     63.7
  12.49    0.156      1.9
 112.11   11.847    178.3

Here is what I want in the output csv or excel file - either csv or excel would work for me:

Intro line here - record of method function:
   Col_A    Col_B
  3.4443    1.443
 10.8876    11.99
Record of local minimum follows:
Trial_1  Trial_2  Trial_3
    1.1     1.49    775.9
   11.5     9.57     87.3
 384.61   77.964     63.7
  12.49    0.156      1.9
 112.11   11.847    178.3

Is there a way to write the list, Pandas, list, Pandas in this order to the csv or excel file?

Answer 1

pd.to_csv() accepts a file handle as input, not just a file name. So you can open a file handle and write multiple files into it. Here's an example:

from __future__ import print_function

with open('output.csv', 'w') as handle:
    for line in list_1:
        print(line, handle)
    df1.to_csv(handle, index=False)
    for line in list_2:
        print(line, handle)
    df2.to_csv(handle, index=False)

Answer 2

The csv module provides your desired functionality:

import csv
with open('SO Example.csv', 'w') as f:
    writer = csv.writer(f, lineterminator='\n')
    writer.writerow(list_1)
    writer.writerow(df1.columns)
    writer.writerows(df1.values)
    writer.writerow(list_2)
    writer.writerow(df2.columns)
    writer.writerows(df2.values)