[Tut] How to Convert Tab-Delimited File to CSV in Python?

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How to Convert Tab-Delimited File to CSV in Python?

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The easiest way to convert a tab-delimited values (TSV) file to a comma-separated values (CSV) file is to use the following three lines of code:

1. Code:

   import pandas as pd
   
   
   
2. Code:

   df = pd.read_csv('my_file.txt', sep='\t', header=None)
   
   
   
3. Code:

   df.to_csv('my_file.csv', header=None)
   
   

We’ll explain this and other approaches in more detail next—scroll down to Method 3 for this exact method.

Problem Formulation

Given a tab-delimited file with one tab character

Code:

'\t'

between two values in a given column.

Input:

Code:

'my_file.tsv'

Figure: File

Code:

'my_file.tsv'

with tab

Code:

'\t'

separated values.

Code:

Alice DataScience $100000 Bob Programmer $90000 Carl Manager $122000 Dave Freelancer $144000

How to convert the tab-delimited values (TSV) to a comma-separated values (CSV) file?

Output:

Code:

'my_file.csv'

Code:

0,Alice,DataScience,$100000 1,Bob,Programmer,$90000 2,Carl,Manager,$122000 3,Dave,Freelancer,$144000

We’ll also look at slight variations of this problem. Let’s go!

Method 1: String Replace Single Tab

The most straightforward way to convert a tab-delimited (TSV) to a comma-separated (CSV) file in Python is to replace each tabular character

Code:

'\t'

with a comma

Code:

','

character using the

Code:

string.replace()

method. This works if two values are separated by exactly one tabular character.

Here’s an example input file

Code:

'my_file.tsv'

:



Here’s an example of some code to convert the tab-delimited file to the CSV file:

Code:

with open('my_file.tsv') as f: # Read space-delimited file and replace all empty spaces by commas data = f.read().replace('\t', ',') # Write the CSV data in the output file print(data, file=open('my_file.csv', 'w'))

Output file

Code:

'my_file.csv'

:



If you have any doubts, feel free to dive into our related tutorials:

• Python String Replace Method
  
  
• Python
  Code:

  open()
  Function
  
  
• Python
  Code:

  print()
  to File
  
  
• Python
  Code:

  print()
  Function
  
  
• Python Context Managers
  

Method 2: Regex Replace Arbitrary Tabs

To replace one

Code:

'\t'

or more tabs

Code:

'\t\t\t'

between two column values with a comma

Code:

','

and obtain a CSV, use the regular expressions operation

Code:

re.sub('[\t]+', ',', data)

on the space-separated

Code:

data

.

If you have any doubts, feel free to dive into our related tutorials:

• Python Regex
  Code:

  re.sub()
  
  
  
• Python Regex
  Code:

  []
  Character Class
  
  
• Python Regex
  Code:

  +
  Quantifier
  
  
• Python Regex Superpower
  

Here’s an example input file

Code:

'my_file.tsv'

, notice the additional tabular characters that may separate two column values:



Here’s an example of some code to convert the TSV to the CSV file:

Code:

import re with open('my_file.txt') as infile: # Read space-delimited file and replace all empty spaces by commas data = re.sub('[ ]+', ',', infile.read()) # Write the CSV data in the output file print(data, file=open('my_file.csv', 'w'))

Output file

Code:

'my_file.csv'

:



Method 3: Pandas read_csv() and to_csv()

To convert a tab-delimited file to a CSV, first read the file into a Pandas DataFrame using

Code:

pd.read_csv(filename, sep='\t+', header=None)

and then write the DataFrame to a file using

Code:

df.to_csv(outfilename, header=None)

.

Here’s an example input file

Code:

'my_file.tsv'

:



Here’s an example of some code to convert the tab-delimited file to the CSV file:

Code:

import pandas as pd # Read space-delimited file df = pd.read_csv('my_file.tsv', sep='\t+', header=None) # Write DataFrame to file df.to_csv('my_file.csv', header=None)

Output file

Code:

'my_file.csv'

:



You can also use the simpler

Code:

sep='\t'

if you are sure that only a single tabular character separates two column values.

If you have any doubts, feel free to dive into our related tutorials:

• Pandas
  Code:

  read_csv()
  
  
  
• Pandas
  Code:

  to_csv()
  
  

Summary

We examined three great ways to convert a space-delimited to a comma-separated CSV file:

• Method 1: String Replace Single Tab
  
  
• Method 2: Regex Replace Arbitrary Tabs
  
  
• Method 3: Pandas
  Code:

  read_csv()
  and
  Code:

  to_csv()
  
  

Thanks for taking the time to read this article, my friend!

Regex Humor

[i]Wait, forgot to escape a space. Wheeeeee[taptaptap]eeeeee. (source)[/i]