import re


def underscore_to_camel(value):
    """
    Convert a value from underscore lower case convention to camel case convention.
    Args:
        value (str): value in underscore lowercase convention.
    Returns:
        value in camel case convention.
    """
    under_pat = re.compile(r'_([a-z])')
    return under_pat.sub(lambda x: x.group(1).upper(), value)