Python : name 'math' is not defined Error?

Question

I am a beginner in python and cant understand why this is happening:

from math import *
print "enter the number"
n=int(raw_input())
d=2
s=0
while d<n :
    if n%d==0:
       x=math.log(d)
       s=s+x
       print d
    d=d+1
print s,n,float(n)/s

Running it in Python and inputing a non prime gives the error

Traceback (most recent call last):
  File "C:Python27mit ocwpset1a.py", line 28, in <module>
    x=math.log(d)
NameError: name 'math' is not defined

Asked By: dannysood

||

Source

Answer 1

Change

from math import *

to

import math

Using from X import * is generally not a good idea as it uncontrollably pollutes the global namespace and could present other difficulties.

Answered By: NPE

Answer 2

You need to import math rather than from math import *.

Answered By: Sam Dolan

Answer 3

You did a mistake..

When you wrote :

from math import *
# This imports all the functions and the classes from math
# log method is also imported.
# But there is nothing defined with name math

So, When you try using math.log

It gives you error, so :

replace math.log with log

Or

replace from math import * with import math

This should solve the problem.

Answered By: Yugal Jindle

Answer 4

How about (when you need only math.pi):

from math import pi as PI

and then use it like PI symbol?

Answered By: TomKo1

Python : name 'math' is not defined Error?

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