Python: Change Variable Value [Examples]

Example 1: Reassigning a Variable

# Initial value
x = 5

# Reassigning the variable
x = 10

# Print the updated value
print(x)
    

Output:

10
    

Example 2: Incrementing a Numeric Variable

# Initial value
count = 0

# Increment the variable
count += 1

# Print the updated value
print(count)
    

Output:

1
    

Example 3: Decrementing a Numeric Variable

# Initial value
quantity = 10

# Decrement the variable
quantity -= 2

# Print the updated value
print(quantity)
    

Output:

8
    

Example 4: Concatenating Strings

# Initial values
first_name = "John"
last_name = "Doe"

# Concatenate strings
full_name = first_name + " " + last_name

# Print the concatenated string
print(full_name)
    

Output:

John Doe
    

Example 5: Updating Lists

# Initial list
fruits = ["apple", "banana", "cherry"]

# Update the list
fruits[1] = "orange"

# Print the updated list
print(fruits)
    

Output:

['apple', 'orange', 'cherry']
    

Example 6: Modifying Dictionary Values

# Initial dictionary
student = {"name": "Alice", "age": 25}

# Modify a dictionary value
student["age"] = 26

# Print the modified dictionary
print(student)
    

Output:

{'name': 'Alice', 'age': 26}
    

Example 7: Multiplying Numeric Variables

# Initial values
length = 5
width = 3

# Multiply variables
area = length * width

# Print the calculated area
print("Area:", area)
    

Output:

Area: 15
    

Example 8: Updating Variables Conditionally

# Initial values
temperature = 25

# Check a condition and update the variable
if temperature > 30:
    status = "Hot"
else:
    status = "Moderate"

# Print the status
print("Temperature Status:", status)
    

Output:

Temperature Status: Moderate
    

Example 9: Swapping Variable Values

# Initial values
a = 5
b = 10

# Swap the values of variables
a, b = b, a

# Print the swapped values
print("a:", a)
print("b:", b)
    

Output:

a: 10
b: 5
    

Example 10: Updating Variables Using a Function

# Initial value
value = 5

# Define a function to update the value
def update_value(num):
    return num * 2

# Update the value using the function
value = update_value(value)

# Print the updated value
print("Updated Value:", value)
    

Output:

Updated Value: 10
    

Example 11: Appending to a List

# Initial list
fruits = ["apple", "banana", "cherry"]

# Append an item to the list
fruits.append("orange")

# Print the updated list
print("Fruits:", fruits)
    

Output:

Fruits: ['apple', 'banana', 'cherry', 'orange']
    

Example 12: Removing an Item from a List

# Initial list
fruits = ["apple", "banana", "cherry"]

# Remove an item from the list
fruits.remove("banana")

# Print the updated list
print("Fruits:", fruits)
    

Output:

Fruits: ['apple', 'cherry']
    

Example 13: Updating Dictionary Values

# Initial dictionary
person = {"name": "Alice", "age": 25}

# Update a dictionary value
person["age"] += 1

# Print the updated dictionary
print("Person:", person)
    

Output:

Person: {'name': 'Alice', 'age': 26}
    

Example 14: Clearing a List

# Initial list
numbers = [1, 2, 3, 4, 5]

# Clear the list
numbers.clear()

# Print the empty list
print("Numbers:", numbers)
    

Output:

Numbers: []
    

Example 15: Deleting a Variable

# Initial value
variable_to_delete = "I will be deleted"

# Delete the variable
del variable_to_delete

# Attempt to print the deleted variable (will raise an error)
try:
    print(variable_to_delete)
except NameError as e:
    print("Variable deleted:", e)
    

Output:

Variable deleted: name 'variable_to_delete' is not defined