numpy and statistics module

[baronmontesqieu]

hello.
I am trying to get familiar with numpy and statstics module on python

the latter is program i made to input any list and try to find the standard deviation of the list

i am getting an error; please check on this.

thank you very much.

the latter is code

import numpy
import statistics

rawstr = raw_input("type a 4-list of integers")
rawstr1 = raw_input("type a 4-list of integers")
rawstr2 = raw_input("type a 4-list of integers")
ival = list(rawstr)
ival1 = list(rawstr1)
ival2 = list(rawstr2)

arr = numpy.array([ival1,ival2,ival3])
statistics.stdev(arr)

the latter is error

Error:
ImportError Traceback (most recent call last)
<ipython-input-1-ffd1ea567921> in <module>()
1 import numpy
----> 2 import statistics
3
4 rawstr = raw_input("type a 4-list of integers")
5 rawstr1 = raw_input("type a 4-list of integers")

ImportError: No module named statistics

thank you