Determining whether a number is positive, negative or zero I am a beginner in Python and am currently learning about making beautiful code.  I've started with a small program.  Can you please review my code?    

def inputAndRes():
    try:
        a = raw_input("Enter no. :- ")
        n = int(a)
    except Exception:
        print "-----------------------------------"
        print "Please Enter No. " , "( The Number you entered is not a number )"
        inputAndRes()
    else:
        if(n&gt;0):
            print "Number is Positive"
        if(n&lt;0):
            print "Number is Negative"
        if(n==0):
            print "Number is ZERO"
        wantRestart()

def checkYN(checkResult):
    if (checkResult == 'Y'):
            inputAndRes()
    if (checkResult == 'N' ):
            print (" !!! Program Quit !!!")
    else:
        print ("Invalid Option Make sure that you type (Y / N)")
        print ("Continue..")
        wantRestart()

def wantRestart():
    print "\nWant to Restart Program, if Yes then Enter 'Y' and if No enter 'N' :- ",
    try:
        checkResult = raw_input(" ")
    except Exception as e:
        print ("Sorry Error Occured: ",e)
    else:
        checkYN(checkResult)        
#...Start of Program...
inputAndRes()
Flow control

The conditions here are mutually exclusive:


if(n&gt;0):
    print "Number is Positive"
if(n&lt;0):
    print "Number is Negative"
if(n==0):
    print "Number is ZERO"



It would be better to rewrite with elif and else:

if n &gt; 0:
    print "Number is Positive"
elif n &lt; 0:
    print "Number is Negative"
else:
    print "Number is ZERO"


Same thing here:


if (checkResult == 'Y'):
        inputAndRes()
if (checkResult == 'N' ):
        print (" !!! Program Quit !!!")
else:
    print ("Invalid Option Make sure that you type (Y / N)")
    print ("Continue..")
    wantRestart()



Should be:

if checkResult == 'Y':
    inputAndRes()
elif checkResult == 'N' :
    print (" !!! Program Quit !!!")
else:
    print ("Invalid Option Make sure that you type (Y / N)")
    print ("Continue..")
    wantRestart()


Finally, instead of raw_input(" "), it would be simpler to write as raw_input().

Writing style

There is an official coding style guide for Python called PEP8. Give it a good read and try to follow it. Your most notable coding style violations:


Spacing around operators: prefer n &gt; 0 instead of n&gt;0

Also, avoid unnecessary parenthesis in if statements, for example if n &gt; 0: is better than if (n &gt; 0):

Function naming should be snake_case instead of camelCase
Put 2 empty lines in front of a function definition


Misc

Instead of running inputAndRestart unconditionally, the common practice is this:

if __name__ == '__main__':
    inputAndRestart()


The advantage of this is that you will be able to import your module without running anything, because the if will only be true when you run the script directly.

Usability

The program wants me to enter Y to restart and N to exit, but I'm kinda lazy to press the shift. It would be great if I could use just y and n. Or even q and Q to exit. An easy way to do that:

if result in 'yY':
    input_and_restart()
elif result in 'nNqQ':
    print (" !!! Program Quit !!!")