Introduction
In Python, probably the most frequent errors that novices and even some seasoned programmers encounter is the NameError: identify 'random' just isn't outlined. This error usually pops up when attempting to make use of the random module with out correctly importing it.
On this Byte, we are going to perceive this error and learn to appropriately import and use the random module in Python.
Understanding the Error
Earlier than we get into fixing the issue, let’s first perceive what this error means. The NameError: identify 'random' just isn't outlined error is raised once you attempt to use the random module, or a perform from it, with out first importing it into your script. It is because Python does not robotically load all modules at startup on account of efficiency causes. This is an instance of this error:
print(random.randint(1, 10))
Output:
NameError: identify 'random' just isn't outlined
As you’ll be able to see, trying to make use of random.randint() with out first importing the random module ends in the NameError.
Importing the random Module
To make use of the random module or another module in Python, you should import it first. The import assertion in Python is used to load a module into your script. This is how one can import it:
import random
print(random.randint(1, 10))
Output:
7
Now, the script works wonderful as a result of we have imported the random module earlier than utilizing its randint perform.
Be aware: Newbies, do not forget that the import assertion must be positioned firstly of your script, earlier than any perform that makes use of the module is known as!
Correct Scoping for Modules
One other factor that may journey up programmers is module scoping. Understanding the scope is necessary, particularly once you’re not importing modules on the prime of your supply file. If you import a module, it is solely obtainable within the scope the place you imported it. So when you import a module inside a perform, it will not be obtainable exterior that perform since that’s out of scope.
This is an instance:
def generate_random_number():
import random
return random.randint(1, 10)
print(generate_random_number())
print(random.randint(1, 10)) # This may increase an error
Output:
5
NameError: identify 'random' just isn't outlined
As you’ll be able to see, the random module just isn’t obtainable exterior the generate_random_number perform. To make a module obtainable to your total script, import it on the prime stage of your script, exterior any perform or class.
Keep away from Importing in attempt/besides Blocks
In Python, it is a frequent observe to make use of attempt/besides blocks to deal with exceptions. Nonetheless, importing modules inside these blocks could cause sudden errors. A standard mistake is to place the import assertion exterior of the attempt block, which might result in a NameError if an error is raised earlier than the import.
This is a code snippet that demonstrates the issue:
attempt:
// Some code...
import random
num = random.randint(1, 10)
besides Exception:
print("Oh no! An error...")
num = random.randint(1, 10) # This might increase an error
On this code, if an exception happens earlier than the import random line, the import assertion will probably be skipped, and any subsequent code that makes use of the random module will fail with the NameError: identify 'random' just isn't outlined error.
Be aware: It is best to keep away from importing modules in attempt/besides blocks. As a substitute, all the time import all essential modules firstly of your script. Importing in these blocks must be reserved for particular circumstances.
By shifting the import assertion exterior the attempt block, you make sure that the module is all the time obtainable in your script, even when the code inside the attempt block raises an exception.
Importing Particular Features from the random Module
As a substitute of importing your entire random module, you’ll be able to import solely the particular features you want. That is finished utilizing the from ... import ... assertion.
from random import randint, alternative
Now, you’ll be able to instantly use randint and alternative with out prefixing them with random.
num = randint(1, 10)
letter = alternative('abc')
Simply ensure that to solely use these perform names when calling them and never random.randint(), for instance, to keep away from the NameError.
Resolving “‘random’ has no attribute ‘X'” Error
The error AttributeError: 'module' object has no attribute 'X' happens once you’re attempting to entry a perform or attribute that does not exist within the module. This may very well be on account of a typo within the perform identify or the perform won’t exist within the module.
import random
num = random.randit(1, 10)
Within the above code, randit is a typo and it must be randint. Correcting the typo will repair the error.
import random
num = random.randint(1, 10)
Conclusion
On this Byte, we have coated fairly just a few potential errors round importing modules, particularly the random module. Particularly, we appeared on the error NameError: identify 'random' just isn't outlined and methods to resolve it.
We have additionally checked out some associated errors that happen when working with the random module, resembling AttributeError: 'module' object has no attribute 'alternative' and methods to repair them.
