Strings of Zeros

2022-12-26.py

question = """
Given a string of any length which contains only digits from 0 to 9,
replace each consecutive run of the digit 0 with its length.

Example:

> replaceZeros('1234500362000440')
> 1234523623441

> replaceZeros('123450036200044')
> 123452362344

> replaceZeros('000000000000')
> 12

> replaceZeros('123456789')
> 123456789
"""

import re
def replaceZeros(num_str):
    out_str = num_str
    for zero_string in re.findall(r'(0+)', num_str):
        zero_string_len = len(zero_string)
        out_str = re.sub(zero_string, str(zero_string_len), out_str, 1)
    return out_str

print(replaceZeros('1234500362000440'))
print(replaceZeros('123450036200044'))
print(replaceZeros('000000000000'))
print(replaceZeros('123456789'))