Python Problem - Topic

Member

Posts: 8,407

Joined: Jan 29 2008

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May 26 2012 02:03am

Trying to input a number between 4-9 but if not 4-9 then i want to raise an error message 'Size must be a number between 4 and 9'

Thats fine if a number is inputed but if i input words it doesnt like the int(size)

How do I change it to get it to display the error message no matter what is put in?

Code

ERROR_SIZE = "Size must be a number between 4 and 9"

size = raw_input('Please insert a vaule 4 and 9: ')
sizeint = int(size)
while sizeint > 9 or sizeint < 4:
print ERROR_SIZE
size = raw_input('Please insert a vaule 4 and 9: ')
sizeint = int(size)

Thanks

Jono

BadKiwi

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May 26 2012 02:35am

def get_board_size():
size = raw_input('Please insert a vaule 4 and 9: ')

while size.isdigit() == False or int(size) > 9 or int(size) < 4:
print ERROR_SIZE
size = raw_input('Please insert a vaule 4 and 9: ')

feored

Member

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Joined: Sep 11 2011

Gold: 16,033.67

May 26 2012 05:10am

Code

while True:
try:
size = int(raw_input("Please insert a value between 4 and 9: \n"))
if size < 4 or size > 9:
raise Exception()
break
except ValueError:
print "Oops! That was no valid number. Try again..."
except:
print "Oops! That number was not between 4 and 9. Try again..."

This post was edited by feored on May 26 2012 05:16am

BreakPoint

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May 26 2012 08:16am

Quote (feored @ May 26 2012 04:10am)

Codewhile True:
try:
size = int(raw_input("Please insert a value between 4 and 9: \n"))
if size < 4 or size > 9:
raise Exception()
break
except ValueError:
print "Oops! That was no valid number. Try again..."
except:
print "Oops! That number was not between 4 and 9. Try again..."

Thank you, someone competent with Python. This guy has it.

rockonkenshin

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Joined: Feb 2 2004

Gold: 434.84

May 26 2012 10:10am

A good rule of thumb (and a slightly self-evident thing that many people tend to forget) when dealing with exceptions in any language is to remember that they should be used only for exceptional conditions. People tend to try to use them for flow control and it usually makes for really bad code.

feored

Member

Posts: 1,999

Joined: Sep 11 2011

Gold: 16,033.67

May 26 2012 11:17am

Quote (rockonkenshin @ May 26 2012 06:10pm)

Indeed I just threw this together in a second and I'm currently working on a codebase with exceptions literally everywhere and it apparently seeped through

Now that I'm reading this again raising an exception if size < 4 or size > 9 is especially stupid.

Code

while True:
size = raw_input('Please insert a value between 4 and 9: \n')
if size.isdigit() == True and 9 > int(size) > 4:
break

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