10.1 Syntax Errors

Syntax errors, also known as parsing errors, are perhaps the most common kind of complaint you get while you are still learning Python:

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

The parser repeats the offending line and displays a little `arrow' pointing at the earliest point in the line where the error was detected. The error is caused by (or at least detected at) the token preceding the arrow: in the example, the error is detected at the keyword print, since a colon (‘:’) is missing before it. The file name and line number are printed so you know where to look in case the input came from a script.