CODEWITHSUNDEEP
python
dannysood
dannysood

Reputation: 1139

Python : name 'math' is not defined Error?

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:\Python27\mit ocw\pset1a.py", line 28, in <module>
    x=math.log(d)
NameError: name 'math' is not defined

Upvotes: 43

Views: 159738

Answers (4)

TomKo1
TomKo1

Reputation: 224

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

from math import pi as PI

and then use it like PI symbol?

Upvotes: 1

Yugal Jindle
Yugal Jindle

Reputation: 45696

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.

Upvotes: 10

NPE
NPE

Reputation: 500663

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.

Upvotes: 72

Sam Dolan
Sam Dolan

Reputation: 32532

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

Upvotes: 8

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