str = 'iAmYourDay'


def aa(a):
    if a.isupper():
        return '_' + a.lower()
    else:
        return a


new_str = ''.join(list(map(aa, str)))
print(new_str)

f27c5a68f672d3c738b5c081a33dfa02bac87fea
<mask token>

<mask token>


def aa(a):
    if a.isupper():
        return '_' + a.lower()
    else:
        return a


<mask token>

<mask token>


def aa(a):
    if a.isupper():
        return '_' + a.lower()
    else:
        return a


<mask token>
print(new_str)

str = 'iAmYourDay'


def aa(a):
    if a.isupper():
        return '_' + a.lower()
    else:
        return a


new_str = ''.join(list(map(aa, str)))
print(new_str)
