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Solve the following problem using Python, implementing the functions described below, one line at a time
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Description:

def _to_camelcase(input_string):
    ''' a helper method to convert python to camelcase'''
    camel_string = ''
    for i in range(len(input_string)):
        if input_string[i] == '_':
            pass
        elif not camel_string:
            camel_string += input_string[i].upper()
        elif input_string[i-1] == '_':
            camel_string += input_string[i].upper()
        else:
            camel_string += input_string[i]
    return camel_string