combine_csv

Based on an idea from https://github.com/ekapope/Combine-CSV-files-in-the-folder/blob/master/Combine_CSVs.py, this small script simply focus on merging CSV/TSV files, by combining either lines or column.

Item	Project site
Source	https://github.com/gmtsciencedev/combine_csv
Documentation	https://combine_csv.readthedocs.io/
Download	https://pypi.org/project/combine-csv/
Keywords	python, csv, merge, combine

Basic usage

The tool can be used either :

• in line mode (default) which use all different CSV to create new lines in a merged CSV,
• or in column mode (using flag -c) which use all different CSV to add new columns, using the first column as an index in all files.

Line mode

combine_csv -i '*.csv' -o my_merged_csv.csv

Thus if folder contains:

1.csv

name,age
Jean,23
Paul,12

2.csv

name,age,sex
Jane,19,female
John,74,male

It will create this file: my_merged_csv.csv

name,age,sex
Jean,23,
Paul,12,
Jane,19,female
John,74,male

Column mode

combine_csv -c -i '*.csv' -o my_merged_csv.csv

Thus if folder contains: 1.csv

task_id,name,desc
1,create,create a new object
2,delete,delete an object

2.csv

task_id,program
1,create.py
2,delete.py
3,random.py

It will create this file: my_merged_csv.csv

task_id,name,desc,program
1,create,create a new object,create.py
2,delete,delete an object,delete.py
3,,,random.py

Main options

See command line combine_csv -h for all options. Here we would like to point the most convinient ones.

As you have seen -i is the input selector which takes a python glob.glob pattern (protect it with single quotes as in the examples above to prevent shell interpretation), and -o give the name of the file (which default to combine.csv)

-s --separator : Change the default field separator from , to whatever you need. For TSV file, say \t (add single quotes around to prevent backslash interpretation by shell, e.g. -s '\t' or -s \\t). This separator will be used to read input files and to write output file. You can chose to have a different output separator with -t option which behaves likewise.

-a --addname : Add the name of the input files (without extension). In line mode, this will add a new column named source (which name can be changed with --source-column option) containing the name of the files. In column mode, this will add the names to non-index columns preceded by an underscore.