Convert snake_case to lowerCamelCase in Python [duplicate]

Question

Trying to replace _(character) with just its Uppercase variant. For example:

hello_string_processing_in_python to helloStringProcessingInPython

Since string is immutable in Python, how can string substitution be done efficiently?

ss = 'hello_string_processing_in_python'
for i in re.finditer('_(\w)', ss):
    ????

Answer 1

You may try this,

>>> s = "hello_string_processing_in_python"
>>> re.sub(r'_([a-z])', lambda m: m.group(1).upper(), s)
'helloStringProcessingInPython'

Answer 2

No split or regex is needed and it also ensures that the first character is lowercase:

lower_camel_case = ss[0].lower() + ss.title()[1:].replace("_", "")
print(lower_camel_case)

helloStringProcessingInPython