How to correct the error?

[Ponomarenko Pavlo]

z = '346 + 324 - 368'
z.split('+', '-')

Error:
Traceback (most recent call last):
  File "<pyshell#17>", line 1, in <module>
    z.split('+', '-')
TypeError: 'str' object cannot be interpreted as an integer

[snippsat]

split() don't work multiple delimiters.
You can use re.spilt().

>>> import re

>>> z = '346 + 324 - 368'
>>> re.split(r'\W+', z)
['346', '324', '368']
>>> '  '.join(re.split(r'\W+', z))
'346 324 368'

\W+ matches any non-word character (equal to [^a-zA-Z0-9_])

[Yoriz]

Adding to the previous answer and explaining the error.
split can be passed two arguments,

1. a string that indicates where to split
   
2. a int specifying the maximum allowed times to split
   

so the error you have is because the second argument that was expected to be an int was actually a str '-'.

If the string in question is always formatted as shown and you are only interested in getting the numbers without using re

z = '346 + 324 - 368'
z.split()[::2]

Output:
['346', '324', '368']

[metulburr]

a non regex method using string methods....

>>> z = '346 + 324 - 368'
>>> x = z.maketrans('+-','..')
>>> x
{43: 46, 45: 46}
>>> y = z.translate(x).split('.')
>>> y
['346 ', ' 324 ', ' 368']

of course at this point its a list and each string is not separate by one single space

>>> a = list(map(str.strip, y))
>>> a
['346', '324', '368']
>>> ' '.join(a)
'346 324 368'

This would not matter of exact format as something like this

z = '346 + 324 - 368 - 368 + 368 + 368 -45 -56- 368'

would still split to this

346 324 368 368 368 368 45 56 368

Using python3.x otherwise you have to import string and convert maketrans line to.... string.maketrans('+-','..')