Posted By: Anonymous
I want to check if a variable exists. Now I’m doing something like this:
try: myVar except NameError: # Do something.
Are there other ways without exceptions?
To check the existence of a local variable:
if 'myVar' in locals(): # myVar exists.
To check the existence of a global variable:
if 'myVar' in globals(): # myVar exists.
To check if an object has an attribute:
if hasattr(obj, 'attr_name'): # obj.attr_name exists.
Answered By: Anonymous
- error LNK2005: xxx already defined in…
- What's the difference between eval, exec, and compile?
- Angular 4/5/6 Global Variables
- How to bind an AngularJS variable as a Polymer global?
- Polymer Dart, global variables and data bindings…
- Why is "except: pass" a bad programming practice?
- Polymer global variables
- Is it a good practice to use try-except-else in Python?
- How to use html template with vue.js
- How to remove MySQL completely with config and…
- Implement global variables in Polymer 1.0
- Ember.js: How to inject dependency into adapter?
- Detect Browser Language in PHP
- coercing to Unicode: need string or buffer, NoneType…
- Polymer global variables document may be wrong~
- Difference between variable declaration syntaxes in…
- How do I observe sub-property changes in Polymer?
- Passport.js in Next.js app not saving user across…
- How to know if an object has an attribute in Python
- How to make global variables "immutable" in Lua/LuaJ?
- How to load bootstrapped models in Backbone.js while…
- How does the "this" keyword work?
- Postgres could not connect to server
- "No such file or directory" error when executing a binary
- Define global variable with webpack
- How to handle errors with boto3?
- Get the name of an object's type
- Manually raising (throwing) an exception in Python
- How can I throw CHECKED exceptions from inside Java…
- Are nested try/except blocks in Python a good…
- Issue: C compiler used for C++ in CMake | CMake + git
- Where do you place a simple variable in the Ember…
- Best practice for shared objects in Backbone/Require…
- Adding Input Value Into An Object (Vue.js)
- Correct way to try/except using Python requests module?
- Data binding between two Polymer elements using polymer 1.0
- How to automate parameters passed into pandas.read_sql?
- Mismatch Detected for 'RuntimeLibrary'
- What is difference between Errors and Exceptions?
- Use of Custom Data Types in VBA
- Overwriting a Backbone Models Change Event
- Can a local variable's memory be accessed outside its scope?
- Length of string in bash
- Perfomance issues with large number of elements in…
- split python source code into multiple files?
- Python: how to assign a name of a list variable to a class
- Twig: in_array or similar possible within if statement?
- Polymer conflict with moment.js?
- Catch multiple exceptions in one line (except block)
- express server redirect issues
- How can I wrap all BeautifulSoup existing…
- How to declare a global variable in php?
- The static keyword and its various uses in C++
- NameError: global name 'xrange' is not defined in Python 3
- Usage of __slots__?
- Unable to pass data from custom pre-handler…
- How to save traceback / sys.exc_info() values in a variable?
- Rails 4 - passing variable to partial
- Global Angular CLI version greater than local version
- error LNK2038: mismatch detected for '_MSC_VER':…
- Best way to test for a variable's existence in PHP;…
- How do I use $scope.$watch and $scope.$apply in AngularJS?
- Server Side Rendering Vue with ASP.NET Core 2
- Throw HttpResponseException or return…
- python: How do I know what type of exception occurred?
- What is exactly the base pointer and stack pointer?…
- PHP class: Global variable as property in class
- What is a NullPointerException, and how do I fix it?
- throwing exceptions out of a destructor
- Use of "global" keyword in Python
- Marionette + i18n in templates
- Catching multiple exception types in one catch block
- Vue.js Retrieving Remote Data for Options in Select2
- Catching FULL exception message
- What are access specifiers? Should I inherit with…
- ASP.NET Core Web API exception handling
- How to resolve "Could not find schema information…
- How to load a custom script with require.js and make…
- Vue v-bind:class not working immediately when…
- Using global variables between files?
- How to serialize SqlAlchemy result to JSON?
- What is a NullReferenceException, and how do I fix it?
- Difference between except: and except Exception as…
- How to place object files in separate subdirectory
- How using try catch for exception handling is best practice
- Understanding checked vs unchecked exceptions in Java
- How to show/hide if variable is null
- Custom Polymer component returning error: unexpected…
- Backbone.js - passing arguments through constructors