Interview question

What is the difference between mutable and immutable data types? - Data Types and Data Structures Mutable और immutable data types में क्या अंतर है?

Answer

Type	Mutable	Immutable
Examples	list, dict, set	int, str, tuple, frozenset
Change in place	Yes	No
Dict key	No	Yes
Performance	Slower	Faster

# Mutable - can change in place
my_list = [1, 2, 3]
my_list[0] = 99  # Changes original

my_dict = {'a': 1}
my_dict['a'] = 2  # Changes original

# Immutable - cannot change, create new
my_tuple = (1, 2, 3)
# my_tuple[0] = 99  # TypeError

my_str = 'hello'
# my_str[0] = 'H'  # TypeError
new_str = 'H' + my_str[1:]  # Create new string

# Immutable types as dict keys
my_dict = {
    (1, 2): 'tuple key',  # OK
    'string': 'value',  # OK
    42: 'number'  # OK
}

# Cannot use mutable types as keys
try:
    my_dict[[1, 2]] = 'list key'  # TypeError
except TypeError:
    print('Lists cannot be keys')

Type	Mutable	Immutable
Examples	list, dict, set	int, str, tuple
Change कर सकते हैं	हाँ	नहीं
Dict key	नहीं	हाँ

my_list = [1, 2, 3]
my_list[0] = 99  # बदल जाता है

my_tuple = (1, 2, 3)
# my_tuple[0] = 99  # Error

# Dictionary keys
my_dict = {(1, 2): 'value'}  # काम करता है
# my_dict[[1, 2]] = 'value'  # Error

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