Replace Leading Whitespace With Other Other Char - Python

I want to replace my leading whitespace with a nbsp; per whitespace. So: spam --> spam eggs -->  eggs spam eggs -->   spam eggs I've seen a

Solution 1:

You don't even need expensive regex here, just strip out the leading whitespace and prepend a number of   characters for the number of stripped characters:

defreplace_leading(source, char=" "):
    stripped = source.lstrip()
    return char * (len(source) - len(stripped)) + stripped

print(replace_leading("spam"))         # spamprint(replace_leading(" eggs"))        #  eggsprint(replace_leading("  spam eggs"))  #   spam eggs

Solution 2:

You can use re.sub with a callback function and evaluate the length of the match:

>>>raw_line = '  spam eggs'>>>re.sub(r"^\s+", lambda m: " " * len(m.group()), raw_line)
'  spam eggs'

Solution 3:

A non regex solution:

s = '  spam eggs'
s_s = s.lstrip()
print(' '*(len(s) - len(s_s)) + s_s)
#   spam eggs