Throwing the error message in Tkinter

[psbasha]

Hi ,

I would like to throw a error/warning message to the user based on the Inputs given.

Case 1) If the inputs are not given correctly.I have to diplaythe message,saying "Enter the correct inputs"

Case 2) In between the functions,if I am getting a wrong input data ,I have to stop further execution of the application and display the error message " Calculated xyz values are wrong ..."

I hope we have to use "try " and "catch' blocks.

Could anybody provide the snippet of the code for catching the above cases error.

Thanks
PSB

[bvdet]

Hi ,

I would like to throw a error/warning message to the user based on the Inputs given.

Case 1) If the inputs are not given correctly.I have to diplaythe message,saying "Enter the correct inputs"

Case 2) In between the functions,if I am getting a wrong input data ,I have to stop further execution of the application and display the error message " Calculated xyz values are wrong ..."

I hope we have to use "try " and "catch' blocks.

Could anybody provide the snippet of the code for catching the above cases error.

Thanks
PSB

It seems you want your code to continue, but loop back to give the user a chance to input valid data. This may not be the best way:

while True:
    data = raw_input("Enter data")
    if test_user_entered_data(data): # pass to a test function, return True if valid
        break # continue to process the valid data
    else:
        print "You entered invalid data. Please enter again."

[bartonc]

Hi ,

I would like to throw a error/warning message to the user based on the Inputs given.

Case 1) If the inputs are not given correctly.I have to diplaythe message,saying "Enter the correct inputs"

Case 2) In between the functions,if I am getting a wrong input data ,I have to stop further execution of the application and display the error message " Calculated xyz values are wrong ..."

I hope we have to use "try " and "catch' blocks.

Could anybody provide the snippet of the code for catching the above cases error.

Thanks
PSB

Creating your own Exception classes is a very useful thing to learn:

class MyAppError(exception):
    def __init__(self, message):
        self.message = message
 
    def __repr__(self):
        return self.message
 
try:
    if A + B + C != ExpectedResult:
         raise MyAppError(" Calculated xyz values are wrong ...")
except MyAppError, msg
    print msg

You can also raise any type of built-in exception the same way. Another trick is to:

try:
    aValue = aList[anIndex]
except IndexError:
    # do something usefull
    raise

Which allows you to intercept the error and then let it continue to propigate up the call chain.