DEV Community

Avnish
Avnish

Posted on

Python remove newline from file

Reading a text file with a specific delimiter in Python can be efficiently accomplished using the csv module, which is designed to work with delimited text files. Below are five examples, each with a different scenario, to illustrate how to use this technique. The provided code snippet reads the first column of a tab-delimited file, skipping the first row (typically headers in CSV files).

Example 1: Reading a Tab-Delimited File

Content of data.txt:

ID  Name    Age
1   John    30
2   Jane    25
3   Bob 28
Enter fullscreen mode Exit fullscreen mode

Code:

import csv
with open('data.txt', 'r') as f:
    first_column = [row[0] for row in csv.reader(f, delimiter='\t')]
    print(first_column[1:])
Enter fullscreen mode Exit fullscreen mode
  • Step 1: The csv.reader object reads the file using the specified delimiter, \t for tab.
  • Step 2: A list comprehension extracts the first element (row[0]) from each row.
  • Step 3: print(first_column[1:]) prints all elements from the first column except the header.

Output:

['1', '2', '3']
Enter fullscreen mode Exit fullscreen mode

Example 2: Reading a Comma-Delimited File

Content of data.csv:

ID,Name,Age
1,John,30
2,Jane,25
3,Bob,28
Enter fullscreen mode Exit fullscreen mode

Modified Code:
Change delimiter='\t' to delimiter=','.

Output:
Similar to Example 1, but this time the file is comma-delimited. The output will be identical, showing the versatility of changing the delimiter based on the file format.

Example 3: Handling Quoted Fields with Commas

Content of data_with_quotes.txt:

"ID","Name","Age"
"1","John, the second","30"
"2","Jane, the first","25"
Enter fullscreen mode Exit fullscreen mode

Modified Code:
Using delimiter=',' and potentially quotechar='"' if fields contain commas.

Output:

['1', '2']
Enter fullscreen mode Exit fullscreen mode

The CSV reader handles the quoted fields correctly, ensuring that commas within quotes are not treated as delimiters.

Example 4: Skipping Comments or Blank Lines

Content of data_with_comments.txt:

# This is a comment
ID  Name    Age

1   John    30
# Another comment
2   Jane    25
Enter fullscreen mode Exit fullscreen mode

Modified Code:
Filters can be applied within the list comprehension to skip comments or blank lines.

Output:

['1', '2']
Enter fullscreen mode Exit fullscreen mode

The output remains focused on the data, showing how Python can be used to pre-process files for reading.

Example 5: Reading a Semi-Colon Delimited File

Content of data_semicolon.txt:

ID;Name;Age
1;John;30
2;Jane;25
Enter fullscreen mode Exit fullscreen mode

Modified Code:
Change delimiter='\t' to delimiter=';'.

Output:

['1', '2']
Enter fullscreen mode Exit fullscreen mode

This example demonstrates how to handle semi-colon delimited files, a common format in some regions and applications.

Each example showcases the flexibility of Python's csv module to handle different data formats and structures, making it a powerful tool for data processing and analysis tasks.

Top comments (0)