Removing text between two characters if a certain substring is found (python)

Question

I am not quite sure why this is happening. I am trying to remove everything between the commas, but it seems to be doing something weird.

import re
jsontext = '123,0test123,456,4test567,789'
for log in re.finditer('test', jsontext):
    print jsontext
    logstart = jsontext.rfind(",",0,log.start())
    logend = jsontext.find(",",log.start())
    jsontext = jsontext[:logstart] + jsontext[logend+1:]
    print logstart
    print logend
    print '\n'
    print jsontext
    print '\n---end---\n'

it is producing

123,0test123,456,4test567,789
3
12


123456,4test567,789

---end---

123456,4test567,789
15
-1


123456,4test567123456,4test567,789

---end---

which leaves with

123456,4test567123456,4test567,789

but I am expecting the end result of

123456789

Why does this happen and how can I fix it?

Answer 1

Fixed this by adding the following:

import re
x = 0
jsontext = '123,0test123,456,4test567,789'
while x == 0:
    log = jsontext.find('test')
    if log <> -1:
        logstart = jsontext.rfind(",",0,log)
                logend = jsontext.find(",",log)
        jsontext = jsontext[:logstart] + jsontext[logend+10:]
    else:
        x = 1
print jsontext

Answer 2

You may have fixed it but your problem is basically the fact that

for log in re.finditer('test',jsontext)

continues to use the original jsontext and not the new value for jsontext.

You can prove this by using this implementation:

import re
jsontext = '123,0test123,456,4test567,789'
for log in re.finditer('test', jsontext):
    log = re.finditer('test',jsontext).next()
    print jsontext
    print log.start()
    logstart = jsontext.rfind(",",0,log.start())
    logend = jsontext.find(",",log.start())
    jsontext = jsontext[:logstart] + jsontext[logend+1:]
    print logstart
    print logend
    print '\n'
    print jsontext
    print '\n---end---\n'

You need to do this in a while loop, not in a for loop.