String Operations

The operator + can be used on strings, but it’s not addition in the mathematical sense. The + operator performs concatenation, which means joining the strings by linking them end-to-end.

>>> fword = 10

>>> sword = 15

>>>print fword+sword

25

>>>fword = ‘10’

>>>sword = ‘15’

>>>print first + second

1015

The Python interpreter will give you an error if you try to concatenate the following variable.

>>>fword = 10

>>>sword = ‘15’

>>>print fword+sword

Traceback (most recent call last):

  File "", line 1, in

TypeError: unsupported operand type(s) for +: 'int' and 'str'

The error means that you can concatenate integers and strings. If you want to concatenate the strings you have to transform first variable into string. You can do this by str(fword)

>>>print str(fword)+sword

1015

The str(variable_name ) transforms the integer into string.

The string can be transformed into integer using int(variable_name). For example:

>>>print fword + int(sword)

25