Question

Is anyone else here using python 2.7.2 for windows?

Answer 1

yea i do.

Answer 2

did you have any problems with defining functions in lecture 4?

Answer 3

nope i did it!

Answer 4

I'm using code swiped from the pdf, but I keep getting NameError: name 'sqrt' not defined. I can't figure out what I've not done.

Answer 5

first "import math"

Answer 6

I think that may be my problem! do I do it thru the menu?

Answer 7

no,just type 'import math' as first line of your program

Answer 8

could you show me a copy of the code?

Answer 9

I tried what you said, but it didn't work... :(

Answer 10

import math
x = 16
ans = 0
if x >= 0:
while ans*ans < x:
ans = ans + 1
print 'ans =', ans
if ans*ans != x:
print x, 'is not a perfect square'
else: print ans
else: print x, 'is a negative number'
def sqrt(x):
ans = 0
if x >= 0:
while ans*ans < x: ans = ans + 1
if ans*ans != x:
print x, 'is not a perfect square'
return None
else: return ans
else:
print x, 'is a negative number'
return None

Answer 11

thanks for ur help. It's not working out for me. I think I need a small break. Maybe when I get back it will look better.

Answer 12

Traceback (most recent call last):
File "<pyshell#22>", line 1, in <module>
sqrt(16)
NameError: name 'sqrt' is not defined

Answer 13

Funny enough, the code works, it's just making the function sqrt(x) that doesn't work. oh well.

Answer 14

my bad,i didn't checked the code just copy paste :(

Answer 15

sqrt() is a function/method of the math module - it is in the math 'namespace'
to access methods of an imported module you have to use module.method

read 9.1 and 9.2 of the Tutorial - I had to refer to it many times on and off as i learned more stuff. The documentation should also be installed on your computer - i find that version easier to use (F1 from within Idle).
http://docs.python.org/tutorial/classes.html#a-word-about-names-and-objects