Python Raise Syntax Error
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you have probably seen some. There are (at least) two distinguishable kinds of errors: syntax errors and exceptions. 8.1. python error types Syntax Errors¶ Syntax errors, also known as parsing errors, are perhaps the python raise custom exception most common kind of complaint you get while you are still learning Python: >>> while True print('Hello python raise valueerror world') File "
Syntax For Raise Clause In Python
in case the input came from a script. 8.2. Exceptions¶ Even if a statement or expression is syntactically correct, it may cause an error when an attempt is made to execute it. Errors detected during execution are called exceptions and are not unconditionally fatal: you will soon learn how to handle them in Python programs. Most exceptions are not handled by programs, however, and result in error messages as shown here: >>> 10 * (1/0) Traceback (most recent call last): File " here for a quick overview of the site Help Center Detailed answers to any questions you might have Meta Discuss the workings and policies of is nested try block possible in python this site About Us Learn more about Stack Overflow the company Business Learn more about hiring python print exception developers or posting ads with us Stack Overflow Questions Jobs Documentation Tags Users Badges Ask Question x Dismiss Join the Stack Overflow Community Stack Overflow is https://docs.python.org/3/tutorial/errors.html a community of 6.2 million programmers, just like you, helping each other. Join them; it only takes a minute: Sign up Python raise SyntaxError up vote 1 down vote favorite I'm cloning a repo for a specific tablet under Android and to get the sources, I've to execute a python script. When I http://stackoverflow.com/questions/17378727/python-raise-syntaxerror execute it I've got this error message : Traceback (most recent call last): File "/home/p1rox/android-imx-sources/.repo/repo/main.py", line 40, in here for a quick overview of the site Help Center Detailed answers to any questions you might have Meta Discuss the workings and policies of this site About Us http://stackoverflow.com/questions/13957829/how-to-use-raise-keyword-in-python Learn more about Stack Overflow the company Business Learn more about hiring developers or posting ads with us Stack Overflow Questions Jobs Documentation Tags Users Badges Ask Question x Dismiss Join the Stack http://sebastianraschka.com/Articles/2014_python_2_3_key_diff.html Overflow Community Stack Overflow is a community of 6.2 million programmers, just like you, helping each other. Join them; it only takes a minute: Sign up How to use “raise” keyword in Python python raise up vote 92 down vote favorite 10 So I have read the official definition of "raise", but I still don't quite understand what it is doing. In simplest terms, what is "raise"? A small example of it's use would help too. python keyword raise share|improve this question edited Sep 9 '13 at 15:44 Nakilon 19.7k86288 asked Dec 19 '12 at 17:27 Capurnicus 1,1883810 12 It's known clause in python as throw in some other languages. –voithos Dec 19 '12 at 17:29 add a comment| 5 Answers 5 active oldest votes up vote 120 down vote accepted It has 2 purposes. yentup has given the first one. It's used for raising your own errors. if something: raise Exception('My error!') The second is to reraise the current exception in an exception handler, so that it can be handled further up the call stack. try: generate_exception() except SomeException, e: if not can_handle(e): raise handle_exception(e) share|improve this answer edited Jan 9 '15 at 9:06 Phalgun 5971618 answered Dec 19 '12 at 17:32 Ignacio Vazquez-Abrams 447k64800956 12 I typed that in and got "global name 'error' is not defined". To others new to Python, you need "raise Exception('My error!')". You replace "error" with your Exception name. A list of standard exceptions you can use is here: docs.python.org/2/library/exceptions.html –Curtis Yallop Feb 28 '14 at 16:59 add a comment| up vote 18 down vote It's used for raising errors. if something: raise Exception('My error!') Some examples here share|improve this answer edited Jan 9 '15 at 11:48 Phalgun 5971618 answered Dec 19 '12 at 17:28 yentup 2,58021234 add a comment| up vote 8 down vot wondering with which version of Python they should start. My answer to this question is usually something along the lines “just go with the version your favorite tutorial was written in, and check out the differences later on.” But what if you are starting a new project and have the choice to pick? I would say there is currently no “right” or “wrong” as long as both Python 2.7.x and Python 3.x support the libraries that you are planning to use. However, it is worthwhile to have a look at the major differences between those two most popular versions of Python to avoid common pitfalls when writing the code for either one of them, or if you are planning to port your project. Sections Sections The __future__ module The print function Python 2 Python 3 Integer division Python 2 Python 3 Unicode Python 2 Python 3 xrange Python 2 Python 3 The __contains__ method for range objects in Python 3 Note about the speed differences in Python 2 and 3 Raising exceptions Python 2 Python 3 Handling exceptions Python 2 Python 3 The next() function and .next() method Python 2 Python 3 For-loop variables and the global namespace leak Python 2 Python 3 Comparing unorderable types Python 2 Python 3 Parsing user inputs via input() Python 2 Python 3 Returning iterable objects instead of lists Python 2 Python 3 Banker’s Rounding Python 2 Python 3 More articles about Python 2 and Python 3 The __future__ module Python 3.x introduced some Python 2-incompatible keywords and features that can be imported via the in-built __future__ module in Python 2. It is recommended to use __future__ imports it if you are planning Python 3.x support for your code. For example, if we want Python 3.x’s integer division behavior in Python 2, we can import it via from __future__ import division More features that can be imported from the __future__ module are listed in the table below: feature optional in mandatory in effect nested_scopes 2.1.0b1 2.2 PEP 227: Statically Nested Scopes generators 2.2.0a1 2.3 PEP 255: Simple Generators division 2.2.0a2 3.0 PEP 238: Changing the Division Operator absolute_import 2.5.0a1 3.0 PEP 328: Imports: Multi-Line and Absolute/Relative with_statement 2.5.0a1 2.6 PEP 343: The "with" Statement print_function 2.6.0a2 3.0 PEP 3105: MPython Exception Message