Access a method's local variables in Python

Was going through a Python Tutorial and have asked a related question here(Code from my previous example and thanks to @emmanuel)

Code:

import math, time
class PrimeFactor:
    def __init__(self):
        pass
    def isprime(self,number):
        start=time.clock()
        fnum = [1,]
        print "Reticulating Splines..."
        last = int(math.ceil(math.sqrt(number)))
        for p in range(2, last + 1):
          开发者_StackOverflow  if (number % p) == 0:
                fnum.append(p)
                fnum.append(number / p)
        # Remove duplicates, sort list
        fnum = list(set(fnum))
        fnum.sort()
        end=time.clock()
        if len(fnum) > 1:
            return number, "is not a prime because of these factors", fnum ,"Time taken", end-start
        else:
            return True, "Time taken", end-start

print "Prime or factor calculator v3 using sqrt(n)"
print #

num =int(raw_input("Enter number: "))
eg=PrimeFactor()

print eg.isprime(num)

From this code, I tried to get the variable fnum which is local to the function(method) isprime, which contains the factor list. Accessing it by calling

print eg.isprime(num).fnum

gave me a error

AttributeError: 'tuple' object has no attribute 'fnum'    

I guess I cannot call a local variable that way.

Plus the code is not reusable. So I decided to do a rewrite, to make it more modular.

Rewritten Code:

import math
class PrimeFactor:
    def __init__(self):
        pass
    def isPrime(self,number):
        fnum = [1,]
        last = int(math.ceil(math.sqrt(number)))
        for p in range(2, last + 1):
            if (number % p) == 0:
                return False
            else:
                return True
    def getFactors(self,number):
        fnum = [1,]
        last = int(math.ceil(math.sqrt(number)))
        for p in range(2, last + 1):
            if (number % p) == 0:
                fnum.append(p)
                fnum.append(number / p)
        # Remove duplicates, sort list
        fnum = list(set(fnum))
        fnum.sort()
        if len(fnum) > 1:
            return fnum
        else:
            return None


num =int(raw_input("Enter number: "))
eg=PrimeFactor()

if eg.isPrime(num):
    print num, "is a Prime Number"
else:
    print num, "is not a prime number"
    print "Factors", eg.getFactors(num)

I had to forgo time calculation. I can calculate time while using an instance.

Question:

Can I access the local variable fnum in my previous example? If yes, How?(I guess no). If no, then is the rewritten code good enough or am I doing it wrong?

The problem with your modification is that you're duplicating the calculus. I understand you just want to get the calculated factors, which just involves creating fnum as an attribute:

import math, time
class PrimeFactor:
    def __init__(self):
        self.fnum = [1,]
        self.elapsedTime = 0
    def getElapsedTime(self):
        return self.elapsedTime
    def getFactors(self):
        return self.fnum
    def isprime(self,number):
        start=time.clock()
        self.fnum = [1,]
        last = int(math.ceil(math.sqrt(number)))
        for p in range(2, last + 1):
            if (number % p) == 0:
                self.fnum.append(p)
                self.fnum.append(number / p)
        # Remove duplicates, sort list
        self.fnum = list(set(self.fnum))
        self.fnum.sort()
        end=time.clock()
        self.elapsedTime = end-start
        return (not len(self.fnum) > 1 )

num =int(raw_input("Enter number: "))
eg=PrimeFactor()

if eg.isprime(num):
    print num, "is a Prime Number", eg.isprime(num)
else:
    print num, "is not a prime number"
    print "Factors", eg.getFactors()
print eg.getElapsedTime()

You could even develop the code a little bit more and take advantage of the previous calculated factors, thus using dynamic programming.

Hope this helps.

You need:

print eg.isprime(num)[2]

(your method is returning a tuple, and you need the third member, that's all)

There is no way to access the local variables of a function from outside that function. You need to explicitly make them available to callers, either by returning them, or by writing their values into a container available to the caller.