hello = 'um'
h = hello
i = 'world2'
k = 5.0
print h ** 2
--------------------------------------------------------------------------- TypeError Traceback (most recent call last) <ipython-input-2-26a5396c5ea3> in <module>() ----> 1 print h ** 2 TypeError: unsupported operand type(s) for ** or pow(): 'str' and 'int'