Last Updated : 30 Aug, 2024
Prerequisites: Python Exception Handling
There are several standard exceptions in Python and NameError is one among them. NameError is raised when the identifier being accessed is not defined in the local or global scope. General causes for NameError being raised are :
1. Misspelled built-in functions:
In the below example code, the print statement is misspelled hence NameError will be raised.
Python
geek = input()
printf(geek)
Output :
NameError: name 'printf' is not defined
2. Using undefined variables:
When the below program is executed, NameError will be raised as the variable geek is never defined.
Python
geeky = input()
print(geek)
Output :
NameError: name 'geek' is not defined
3. Defining variable after usage:
In the following example, even though the variable geek is defined in the program, it is defined after its usage. Since Python interprets the code from top to bottom, this will raise NameError
Python
print(geek)
geek = "GeeksforGeeks"
Output :
NameError: name 'geek' is not defined
4. Incorrect usage of scope:
In the below example program, the variable geek is defined within the local scope of the assign function. Hence, it cannot be accessed globally. This raises NameError.
Python
def assign():
geek = "GeeksforGeeks"
assign()
print(geek)
Output :
NameError: name 'geek' is not definedHandling NameError
To specifically handle NameError in Python, you need to mention it in the except statement. In the following example code, if only the NameError is raised in the try block then an error message will be printed on the console.
Python
def geek_message():
try:
geek = "GeeksforGeeks"
return geeksforgeeks
except NameError:
return "NameError occurred. Some variable isn't defined."
print(geek_message())
Output :
NameError occurred. Some variable isn't defined.
RetroSearch is an open source project built by @garambo | Open a GitHub Issue
Search and Browse the WWW like it's 1997 | Search results from DuckDuckGo
HTML:
3.2
| Encoding:
UTF-8
| Version:
0.7.4