How to Modify an Integer Argument in Python Like Changing an Array's Value?

How can I modify an integer value that is passed as an argument in Python, similar to how I would change the value of an array?

def modify_array(arr):
    arr[0] = 10  # Change the first element of the array

my_array = [1, 2, 3]
modify_array(my_array)
print(my_array)  # Output: [10, 2, 3]

In Python, when you pass an integer to a function, you cannot modify the original value since integers are immutable. However, you can modify mutable objects like lists or dictionaries. This article explains how to work around this limitation and achieve similar results.

# Using a list to modify an integer 
def modify_integer_value(value):
    value[0] += 1  # Increment the integer inside the list

integer_value = [5]  # Wrap the integer in a list
modify_integer_value(integer_value)
print(integer_value[0])  # Output: 6

Causes

• Integers are immutable in Python, meaning their value cannot be changed once assigned.
• When an integer is passed as an argument, only a reference to the integer is sent, not the integer itself.

Solutions

• Use a mutable container like a list to wrap the integer, enabling you to modify its contained value.
• Return the modified value from the function and reassign it to the variable.

Mistake: Expecting the integer itself to change when passed to a function.

Solution: Wrap the integer in a list to allow modification through passed references.

Mistake: Not returning the new integer value from the function.

Solution: Always return altered values so that the original variable can be updated.