Merge content of two csv files in alternate rows

Question

I have two CSV files
csv1:

header
a
b
c

csv2:

header
e
f
g

I want to merge these two files to another CSV in alternate rows like
output.csv:

header
a
e
b
f
c
g

Can this be done? Thanks in advance

Asked By: Joz

||

Source

Answer 1

Will definitly not be the fastest way but it works

import pandas as pd
from itertools import chain, zip_longest

x = pd.DataFrame()
x["header"] = [1, 3, 5, 7]

y = pd.DataFrame()
y["header"] = [2, 4, 6, 8, 10, 21]

chained = list(chain.from_iterable(zip_longest(x["header"].to_list(), y["header"].to_list())))
df = pd.DataFrame()
df["header"] = chained
df = df.dropna()

Answered By: Achille G

Answer 2

Assuming csv 1 read into df1

Assuming csv 2 read into df2

df1 = pd.DataFrame({'header': ['a', 'b', 'c']})
df2 = pd.DataFrame({'header': ['d', 'e', 'f']})

print(pd.concat(
    [df1, df2], axis=1
).stack().reset_index(1, drop=True))

output #

Answered By: Bhargav

Answer 3

A more "traditional" Python approach that doesn’t require any external dependencies.

with open("csv1.txt") as f1, open("csv2.txt") as f2, open("output.txt", "w") as fo:
    csv1, csv2 = f1.readlines(), f2.readlines()
    header, _ = csv1.pop(0), csv2.pop(0)
    output = [header]
    for i in range(min(len(csv1),len(csv2))):
        output.extend([csv1[i], csv2[i]])
    fo.writelines(output)

Answered By: fbattello

Merge content of two csv files in alternate rows

Question:

Answers: