Global name 'x' is not defined

Question

Alright so my guidelines are:

1. Write a program to generate 10-character strings of random lower case, upper case letters and numbers.
2. Write a program to read in random 10-character strings from (1)—(1) will be a function in part (2)— and characterize it as gibberish.
3. Pick ten names out of the phone book and characterize them as gibberish using your function in (2).

I am having trouble with x not being defined. I have added ellipses to help condense a bit. So the program is:

import random

import math


def randstr():
    global x
    int(x=0)
    a = ('abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ0123456789')
    rs = ((random.choice(a)) + (random.choice(a)) + (random.choice(a)) + (random.choice(a)) + (random.choice(a)) + (random.choice(a)) + (random.choice(a)) + (random.choice(a)) + (random.choice(a)) + (random.choice(a)))
    print rs
    if rs[0] == 'A' or 'B' or 'C' or 'D' or 'E' or 'F' or 'G' or 'H' or 'I' or 'J' or 'K' or 'L' or 'M' or 'N' or 'O' or 'P' or 'Q' or 'R' or 'S' or 'T' or 'U' or 'V' or 'W' or 'X' or 'Y' or 'Z':
        x += 1
    if rs[0] == 'a' or 'b' or 'c' or 'd' or 'e' or 'f' or 'g' or 'h' or 'i' or 'j' or 'k' or 'l' or 'm' or 'n' or 'o' or 'p' or 'q' or 'r' or 's' or 't' or 'u' or 'v' or 'w' or 'x' or 'y' or 'z':
        x += 1
    elif rs[1] == 'a' or 'b' or 'c' or 'd' or 'e' or 'f' or 'g' or 'h' or 'i' or 'j' or 'k' or 'l' or 'm' or 'n' or 'o' or 'p' or 'q' or 'r' or 's' or 't' or 'u' or 'v' or 'w' or 'x' or 'y' or 'z':
        x += 1
    ...

    elif rs[9] == 'a' or 'b' or 'c' or 'd' or 'e' or 'f' or 'g' or 'h' or 'i' or 'j' or 'k' or 'l' or 'm' or 'n' or 'o' or 'p' or 'q' or 'r' or 's' or 't' or 'u' or 'v' or 'w' or 'x' or 'y' or 'z':
        x += 1
    if rs[1] == 'A' or 'B' or 'C' or 'D' or 'E' or 'F' or 'G' or 'H' or 'I' or 'J' or 'K' or 'L' or 'M' or 'N' or 'O' or 'P' or 'Q' or 'R' or 'S' or 'T' or 'U' or 'V' or 'W' or 'X' or 'Y' or 'Z':
        x -= 2
    ...

    elif rs[9] == 'A' or 'B' or 'C' or 'D' or 'E' or 'F' or 'G' or 'H' or 'I' or 'J' or 'K' or 'L' or 'M' or 'N' or 'O' or 'P' or 'Q' or 'R' or 'S' or 'T' or 'U' or 'V' or 'W' or 'X' or 'Y' or 'Z':
        x -= 2
    if rs[0] == '1' or '2' or '3' or '4' or '5' or '6' or '7' or '8' or '9' or '0':
        x -= 2
        if rs [1] == 'a' or 'b' or 'c' or 'd' or 'e' or 'f' or 'g' or 'h' or 'i' or 'j' or 'k' or 'l' or 'm' or 'n' or 'o' or 'p' or 'q' or 'r' or 's' or 't' or 'u' or 'v' or 'w' or 'x' or 'y' or 'z' or 'A' or 'B' or 'C' or 'D' or 'E' or 'F' or 'G' or 'H' or 'I' or 'J' or 'K' or 'L' or 'M' or 'N' or 'O' or 'P' or 'Q' or 'R' or 'S' or 'T' or 'U' or 'V' or 'W' or 'X' or 'Y' or 'Z':
            x -= .25
        ...

        elif rs [9] == 'a' or 'b' or 'c' or 'd' or 'e' or 'f' or 'g' or 'h' or 'i' or 'j' or 'k' or 'l' or 'm' or 'n' or 'o' or 'p' or 'q' or 'r' or 's' or 't' or 'u' or 'v' or 'w' or 'x' or 'y' or 'z' or 'A' or 'B' or 'C' or 'D' or 'E' or 'F' or 'G' or 'H' or 'I' or 'J' or 'K' or 'L' or 'M' or 'N' or 'O' or 'P' or 'Q' or 'R' or 'S' or 'T' or 'U' or 'V' or 'W' or 'X' or 'Y' or 'Z':
            x -= .25

    ...

        elif rs [8] == 'a' or 'b' or 'c' or 'd' or 'e' or 'f' or 'g' or 'h' or 'i' or 'j' or 'k' or 'l' or 'm' or 'n' or 'o' or 'p' or 'q' or 'r' or 's' or 't' or 'u' or 'v' or 'w' or 'x' or 'y' or 'z' or 'A' or 'B' or 'C' or 'D' or 'E' or 'F' or 'G' or 'H' or 'I' or 'J' or 'K' or 'L' or 'M' or 'N' or 'O' or 'P' or 'Q' or 'R' or 'S' or 'T' or 'U' or 'V' or 'W' or 'X' or 'Y' or 'Z':
            x -= .25
    return rs

print randstr()

randstr()

Answer 1

So if you were to add an x=0 or just x=int(0) at the beginning of your code it would work fine, because you are attempting to define x= as an int() which is not possible.

import random

import math

def randstr():
    # I removed the 'global x' you should not need it
    x=0             # I made the change for you
    a = ('abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ0123456789')

This should fix your problem of 'x not defined' and you should also be able to get rid of the global x

Answer 2

There are some other errors you need to notice before moving forward.

First problem is in your if statements.

Take a look at this example:

string = "foo"
if string == "foo" or "bar":
    dosomething()

To the human eye, that looks correct, but the computer sees it differently. When you are combining conditions with and or or, the computer checks the conditions left to right. So in this case, the computer sees:

If string is equal to foo or if bar

The second condition, after the or is the same as saying if bar == True: Bar is a string, and any string is always true, so the dosomething() function will always execute. This can be fixed by changing the above example to:

string = "foo"
if string == "foo" or string == "bar":
    dosomething()

Now the computer will execute it as:

If string is equal to foo or if string is equal to bar

Simplifying your code

The second thing I want to point out is one of the number one rules in programming: if you're typing the same thing multiple times, there is probably a better way

In your code, imagine replacing the already long conditions with if rs[9] == 'A' or rs[9] == 'B', etc. It's going to get extremely long and messy. It would be much simpler to make a list of the alphabet, and check your variable against the list. For example:

alpha_list = ['A','B','C'] # etc through 'Z'
if rs[0] in alpha_list:
    dosomething()

The in keyword tells Python to check if the value of rs[0] is in the list alpha_list, or in other words, if it is a letter in the alphabet. Now you can replace all those long messy conditionals with a much shorter, cleaner solution :)

As aIKid pointed out, a string is also an iterable so you could replace the list with a string of all the letters (alphabet = "ABCDEF"...). Either one would work.

As for the original answer to your question, aIKid answered it perfectly, I just figured I'd try to shed some light on some other ways to help you improve!

Answer 3

Instead of int(x=0) - calling a function - you have to declare it:

x = 0

Also, you don't seem to need to have the global x in your function.

So, here is a part of your function:

def randstr()
    x = 0
    #some more code
    #...
    return rs

And there's still a couple more problems.

First, the declaration of rs. What you're using is +, but you should use ,, or else python will just sum all of the values, and returns a number. Remove the unnecessary brackets as well:

rs = [random.choice(a), random.choice(a), ...]

Or just use a loop:

rs = []
for i in range(10): #creating 10 random numbers
    rs.append(random.choice(a))

Your if statement also doesn't do what you think it does. Use the in operator instead:

if rs[0] in 'abcdefghijklmnopqrstuvwxyz':
   ...

And similarly for other conditional statements. Hope this helps!