Python woes

1. Aug 1, 2008

OrbitalPower

python woes:

Code (Text):
~/code/python$cat five.py #!/usr/bin/env python x = input('Enter a five digit number: ') while (not(x < 10000 and x > 99999)): x = input('Five digits please: ') firstDigit = x / 10000 secondDigit = (x / 1000) % 10 thirdDigit = (x / 100) % 10 fourthDigit = (x / 10) % 10 fifthDigit = x % 10 print "The digit a is", firstDigit, secondDigit, thirdDigit, fourthDigit, fifthDigit (1)~/code/python$ ./five.py
Enter a five digit number: 54
Traceback (most recent call last):
File "./five.py", line 5, in ?
x = input('Five digits please: ')
File "<string>", line 0, in ?

I don't understand why it asks for five digits again.

Code (Text):
x = input('Enter a five digit number: ')
while (x <= 9999 or x >= 99999):
x = input('Five digits please: ')
The statements should have been equivalent but it causes problems when I do it the first way.

In java:

x = input.nextInt();
while (!(x > 10000 && x < 99999))
{
System.out.println("Five digits retard: ");
x = input.nextInt();
}

It works like it's supposed to i believe.

Last edited: Aug 1, 2008
2. Aug 1, 2008

mgb_phys

The python code throws an exception when you try and divide the work 'dang' by 10000

The java code "input.nextInt()" makes the input an int (I don't know java, presumably it returns 0 for 'dang'?)

3. Aug 1, 2008

rootX

I don't know python, but have you tried others way like

e.g.
x = 0
while (not(x < 10000 and x > 99999)):
x = input('Five digits please: ')

or put while in different way:
while (not(x < 10000)):
while (not(x > 99999)):

Usually when the code doesn't work I try to use different ways..

4. Aug 1, 2008

OrbitalPower

I typed "dang" because i believe it should have exited the while loop at that point.

Another equivalent statement would be not(x>10000) or not(x < 99999).

I will try them, but really I can already can get it to work fine, I just wondered why it'd stay in the loop on seemingly equivalent statements.

5. Aug 1, 2008

rootX

one way is to debug..
Code (Text):

x = 50000; // try 10000, 99999, 9999, upperlimit+1 ..
//Print x, boolean, ...
while (not(x < 10000 and x > 99999)):
PRINT "I am in loop"

PRINT "I am out"

6. Aug 2, 2008

durt

"not(x < 10000 and x > 99999)"

Think about this for a moment. When will a number ever be both less than 10000 and greater than 99999? Never! So this statement is always true.

7. Aug 2, 2008

OrbitalPower

Yes, I wrote the signs the wrong way in the python version for some reason and wasn't paying attention. I'm sure it'll work when I reverse them.

8. Aug 2, 2008

Hurkyl

Staff Emeritus
Incidentally, python has some syntactic sugar for intervals: your test could be

while not (10000 <= x <= 99999):