How to delete/ignore an entire line in a string if there is a certain character in that line using Python?

Question

If a multi-line string contains a certain character like '$', how can I erase/ignore the whole line that character reside?

Note: The task is to get rid of any lines containing a certain character and not empty lines.

testString = """unknown value 1
                unknown value 2
                unknown value 3
                $ unknown value 4
                unknown value 5"""

Possible duplicate of [What's a quick one-liner to remove empty lines from a python string?](https://stackoverflow.com/questions/1140958/whats-a-quick-one-liner-to-remove-empty-lines-from-a-python-string) — Sayse, Oct 31 '19 at 19:02

score 1 · Accepted Answer · answered Oct 31 '19 at 19:23

First, you can split the string into a list of lines using the splitlines function. Then, using list comprehension you can iterate through the lines and test each line for the presence of "$", and return a new list of lines without any lines containing "$". Then you would recombine the new list with "\n" (the newline character) back into a string.

Here is the code:

testString = """unknown value 1
                unknown value 2
                unknown value 3
                $ unknown value 4
                unknown value 5"""

newTestString = "\n".join([x.strip() for x in testString.splitlines() if "$" not in x])

score 0 · Answer 2 · answered Oct 31 '19 at 19:04

0

Create a generator, yielding that sring splitted by new line character. Instantiate that generator and in loop check it's output. If it (line) contains your special character, call next on the generator.

answered Oct 31 '19 at 19:04

Jakub Červinka

37
7

Ahmed I. Elsayed · Answer 3 · 2019-10-31T22:47:34.613

0

first, split the string into an array in which each elemnt is a line

myLines = testString.splitlines()

this will output an array each element was a line in your string, now loop the contents of this array and if you find an element with '$' , just remove it

for line in myLines:
    for character in line:
       if character == '$'
          myLines.remove(line)

there's another method called strip() which may suit your needs too, try searching for it

edited Oct 31 '19 at 22:47

answered Oct 31 '19 at 19:06

Ahmed I. Elsayed

2,013
2
17
30

This method will remove the character itself. Can I manipulate the code to take out the whole line instead? – Shehan Fernandez Oct 31 '19 at 21:57
This won't manipulate the character, this will till if the character exists, and if it exists then delete the whole array element – Ahmed I. Elsayed Oct 31 '19 at 21:59
if character == '$' will check if there's $ char, then `myLines.remove(line)` to delete the whole line containing the character – Ahmed I. Elsayed Oct 31 '19 at 22:00

How to delete/ignore an entire line in a string if there is a certain character in that line using Python?

3 Answers3