raw_input and ints

gistfile1.py

In [13]: a = raw_input("Name ")
Name Steven

In [14]: a
Out[14]: 'Steven'

In [15]: type(a)
Out[15]: str

In [16]: a = raw_input("Number ")
Number 23

In [17]: a
Out[17]: '23'

In [18]: type(a)
Out[18]: str

In [19]: a = int(a)

In [20]: a
Out[20]: 23

In [21]: type(a)
Out[21]: int

In [22]: a = raw_input("Name ")
Name steven

In [23]: int(a)
---------------------------------------------------------------------------
ValueError                                Traceback (most recent call last)
/home/steven/<ipython-input-23-c8db2292b237> in <module>()
----> 1 int(a)

ValueError: invalid literal for int() with base 10: 'steven'