How can we change the id of an immutable string in Python?

In Python, a string is a sequence of characters. It's a type of data that represents text values, such as words, sentences, or even entire documents. Strings in Python are enclosed in either single quotes ('...') or double quotes ("..."), and can include alphanumeric characters, symbols, whitespace, and more.

As an immutable object, a string's ID cannot be changed in Python. As long as a new string that has the same value as the original string (valid only for small string literals), the ID of both the strings will remain same.

In Python, small string literals (strings with only ASCII characters) that have the same value are interned by the interpreter, meaning that they will have the same ID.

However, for larger strings or strings with non-ASCII characters, even if they have the same value, they will generally have different IDs because they will not be interned.

Here are three different ways to achieve this:

Using String Concatenation

Example

Here, we concatenate an empty string to the original string to create a new string with the same value. Since we are concatenating with an empty string, it doesn't change the value of the original string, so it creates a new string with the same ID.

# create a string
my_string = "Hello, world!"
# create a new string with the same value but a different ID using concatenation
new_string = my_string + ""
# check IDs of both strings

print(my_string)
print(new_string)

print(id(my_string))
print(id(new_string))

Output

Hello, world!
Hello, world! 
140045518101040
140045518101040

Using string concatenation to create a new string

Example

In this example, we are creating a new string by concatenating the word "Goodbye" with a slice of the original string that starts at index 5 (i.e., after the "Hello" part). This creates a new string with the value "Goodbye, world!", which has a different ID than the original string.

# create a string
my_string = "Hello, world!"
# create a new string with a different ID
new_string = "Goodbye" + my_string[5:]
# print the original string and the new string
print("Original string:", my_string)
print("New string:", new_string)
print(id(my_string))
print(id(new_string))

Output

Original string: Hello, world!
New string: Goodbye, world!
139898304986544
139898304917744

Using the string replace() Method to Create a New String

Example

In this example, we are creating a new string by using the string replace() method to replace the word "Hello" in the original string with the word "Goodbye". This creates a new string with the value "Goodbye, world!", which has a different ID than the original string.

# create a string
my_string = "Hello, world!"

# create a new string with a different ID
new_string = my_string.replace("Hello", "Goodbye")
# print the original string and the new string
print("Original string:", my_string)
print("New string:", new_string)
print(id(my_string))
print(id(new_string))

Output

Original string: Hello, world!
New string: Goodbye, world!
139898304554928
139898304555120

Using string Formatting to Create a New String

Example

In this example, we are creating a new string by using string formatting to insert a slice of the original string into a new string template. The slice starts at index 7 (i.e., after the comma and space), so the new string has the value "Goodbye, world!". This new string has a different ID than the original string.

# create a string

my_string = "Hello, world!"

# create a new string with a different ID
new_string = "Goodbye, {}".format(my_string[7:])
# print the original string and the new string
print("Original string:", my_string)

print("New string:", new_string)
print(id(my_string))

print(id(new_string))

Output

Original string: Hello, world!
New string: Goodbye, world!
139898304805808
139898304806256

Using the string() Constructor

Example

Here, we use the string constructor to create a new string with the same value. In Python, small string literals (strings with only ASCII characters) that have the same value are interned by the interpreter, meaning that they will have the same ID.

# create a string
my_string = "Hello, world!"

# create a new string with the same value using the string constructor
new_string = str(my_string)
# check IDs of both strings
print(my_string)
print(new_string)
print(id(my_string))
print(id(new_string))

Output

Hello, world!
Hello, world!
140704360063024
140704360063024

Using Slicing

Example

Here, we use slicing to create a new string with the same value as the original string. Slicing with no start or end index returns a copy of the original string.

In Python, small string literals (strings with only ASCII characters) that have the same value are interned by the interpreter, meaning that they will have the same ID.

# create a string
my_string = "Hello, world!"
# create a new string with the same value using slicing
new_string = my_string[:]
# check IDs of both strings
print(my_string)
print(new_string)
print(id(my_string))
print(id(new_string))

Output

Hello, world!
Hello, world!
140321283842096
140321283842096

Conclusion

In conclusion, if two string objects have the same value and that value is a small string literal, they will have the same ID. However, for larger strings or strings with non-ASCII characters, even if they have the same value, they will generally have different IDs because they will not be interned.