I was practicing some regex using re module. I wonder how can we change only some numbers from the string.
a1 = 'images1/b100.png'
# required:
a2 = 'images2/b100.png'
My attempt:
import re
a1 = 'images1/b100.png'
nums = list(map(int, re.findall(r'\d+', a1)))
num0 = nums[0]
a2 = a1.replace(str(num0), str(num0+1))
You can provide an argument to only replace the first occurence.
Change:
a2 = a1.replace(str(num0), str(num0+1))
To:
a2 = a1.replace(str(num0), str(num0+1), 1)
As mentioned here: https://docs.python.org/3/library/stdtypes.html
str.replace(old, new[, count])
Return a copy of the string with all occurrences of substring old replaced by new. If the optional argument count is given, only the first count occurrences are replaced.
Below is the Answer,
a2.replace("b200","100")
Result: 'images2/100.png'
Please let me know if you have any questions.
you could type:
a2 = a1.replace(str(num0), str(num0+1), 1)
import re
a1 = 'images1/b100.png'
matches = re.match( r'^(.*)(\d+)(\/.*)$', a1)
a2 = matches.group(1)+str(int(matches.group(2))+1)+matches.group(3)
^(.*)(\d+)(\/.*)$: A path ending with a digit and any filename.
'images1/folder100/hello1.png' required is 'images2/folder100/hello2.png' This answer gives different result.
1to2, but which number do you want to change generally? Is it to always change the first digit to a2? Or add one to the first number? Or change the first number that's before a/to a2? It also would be great if you could show more examples of inputs and your desired output.