Clever Geek Handbook

How do I add something after each number in a line in PYTHON?

Let's say I want to change the line "A = (x + 2. ) * (y + 3. ) - 1 '

to

'A = (x + 2.0e0 ) * (y + 3.0e0 ) - 1.0e0 '.

Every number like 2. or just 2 must be changed. How to do it?

Thank you so much!

+3


source to share


2 answers


Given the comment you wrote, this regex should work:

import re

str = 'A = (x+2.)*(y+3.)-1'
print re.sub(r'(\d+)\.?',r'\1.0e0',str)

Output:

A = (x+2.0e0)*(y+3.0e0)-1.0e0


Regexp explanation:

  • (...)

    - means a capture group that you need to capture for reuse during replacement
  • \d

    - means any number equivalent to [0-9]
  • +

    - means 1 or more events equivalent {1,}

  • \.?

    - means we want either 0 or 1 dot

    . ?

    equivalent to{0,1}

Instead:

  • \1

    - means that we want to take the first group of captured and insert it here
+6


source


You need to look at re

module . In particular, re.sub()

. Read all the documentation for this function. He can do some pretty powerful things. Either that or some kind of construct for match in re.findall()

.



+2


source






More articles:


All Articles