Different Forms of Assignment Statements in Python

We use Python assignment statements to assign objects to names. The target of an assignment statement is written on the left side of the equal sign (=), and the object on the right can be an arbitrary expression that computes an object.

There are some important properties of assignment in Python :-

• Assignment creates object references instead of copying the objects.
• Python creates a variable name the first time when they are assigned a value.
• Names must be assigned before being referenced.
• There are some operations that perform assignments implicitly.

Assignment statement forms :-

1. Basic form:

This form is the most common form.

student = 'Geeks'
print(student)

OUTPUT

Geeks

2. Tuple assignment:

# equivalent to: (x, y) = (50, 100)
x, y = 50, 100

print('x = ', x)
print('y = ', y)

OUTPUT

x = 50 
y = 100

When we code a tuple on the left side of the =, Python pairs objects on the right side with targets on the left by position and assigns them from left to right. Therefore, the values of x and y are 50 and 100 respectively.

3. List assignment:

This works in the same way as the tuple assignment.

[x, y] = [2, 4]

print('x = ', x)
print('y = ', y)

OUTPUT

x = 2
y = 4

4. Sequence assignment:

In recent version of Python, tuple and list assignment have been generalized into instances of what we now call sequence assignment – any sequence of names can be assigned to any sequence of values, and Python assigns the items one at a time by position.

a, b, c = 'HEY'

print('a = ', a)
print('b = ', b)
print('c = ', c)

OUTPUT

a = H
b = E
c = Y

5. Extended Sequence unpacking:

It allows us to be more flexible in how we select portions of a sequence to assign.

p, *q = 'Hello'

print('p = ', p)
print('q = ', q)

Here, p is matched with the first character in the string on the right and q with the rest. The starred name (*q) is assigned a list, which collects all items in the sequence not assigned to other names.

OUTPUT

p = H
q = ['e', 'l', 'l', 'o']

This is especially handy for a common coding pattern such as splitting a sequence and accessing its front and rest part.

ranks = ['A', 'B', 'C', 'D']
first, *rest = ranks

print("Winner: ", first)
print("Runner ups: ", ', '.join(rest))

OUTPUT

Winner: A
Runner ups: B, C, D

6. Multiple- target assignment:

x = y = 75

print(x, y)

In this form, Python assigns a reference to the same object (the object which is rightmost) to all the target on the left.

OUTPUT

75 75

7. Augmented assignment :

The augmented assignment is a shorthand assignment that combines an expression and an assignment.

x = 2

# equivalent to: x = x + 1
x += 1

print(x)

OUTPUT

3

There are several other augmented assignment forms:

-=, **=, &=, etc.