Getting Error "invalid syntax" in Python

[kyosang]

I am new to the Python programming language. After making a code in Python, when I am trying to run my code I am getting an error. The following is the error that I am getting

>>> while True print 'Hello world'
  File "<stdin>", line 1, in ?
    while True print 'Hello world'
                   ^
SyntaxError: invalid syntax

Also many times I get the exceptions. Please tell me some code for handling the exceptions. Hoping that someone will help me soon..!!

[CodGuru]

Since you are new that's why you think that this is very tedious job. but actually its simple to troubleshoot such errors. In Python, the parser repeats the offending line and displays a little `arrow' pointing at the earliest point in the line where the error was detected. In your code the error is caused by the token preceding the arrow. So now you came to know that the error is detected at the keyword print. The error was generated, since you missed the colon (":") before it.

[Viensterrr]

I am trying to explain you what are an exceptions. Even if a statement or expression is syntactically correct, it may cause an error when an attempt is made to execute it. Exceptions are nothing but the errors that are detected during an execution of the program. Exceptions are not unconditionally fatal. The exceptions come in different types, and the type is printed as part of the message. Standard exception names are built-in identifiers (not reserved keywords). Hope that you got the basic concept of the exceptions.!

[Solitario]

For handling the exceptions, the Handling Exceptions are used. It is possible to write programs that handle selected exceptions. I have provided you with an example which asks the user for input until a valid integer has been entered, but allows the user to interrupt the program. You will understand if you look at the following example :

>>> while True:
     try:
         x = int(raw_input("Please enter a number: "))
         break
     except ValueError:
         print "That was not a valid number. You will have to try again..."

[void]

While handling the exceptions you always use the try statement. I have explained the working of the try statement, which is as follows :

1. First, the try clause (the statement(s) between the try and except keywords) is executed.
2. The except clause is skipped, if there is no exception and execution of the try statement is finished at that instant.
3. The rest of the clause is skipped, if an exception occurs during execution of the try clause. The except clause is executed, if its type matches the exception named after the except keyword and then execution continues after the try statement.
4. If an exception occurs which does not match the exception named in the except clause, it is passed on to outer try statements; if no handler is found, it is an unhandled exception and execution stops with a message.

[Praetor]

Many times using the raise statement proves beneficial to the programmer. The raise statement allows the programmer to force a specified exception to occur. You can check the following example for detail :

>>> raise NameError, 'HiEveryone'
Traceback (most recent call last):
  File "<stdin>", line 1, in ?
NameError: HiEveryone