Python hash() Function

Python has() function is used to get the hash value of an object. Python calculates the hash value by using the hash algorithm. The hash values are integers an used to compare dictionary keys during a dictionary lookup. We can hash only these types:

Hashable types: * bool * int * long * float * string * Unicode * tuple * code object

We cannot hash of these types:

Non-hashable types: * bytearray * list * set * dictionary * memoryview

Signature

Parameters

object: The object of which hash, we want to get. Only immutable types can be hashed.

Return

It returns the hash value of an object.

Let's see some examples of hash() function to understand it's functionality.

Python hash() Function Example 1

Here, we are getting hash values of integer and float values. See the below example.

# Python hash() function example
# Calling function
result = hash(21) # integer value
result2 = hash(22.2) # decimal value
# Displaying result
print(result)
print(result2)

Output:

21
461168601842737174

Python hash() Function Example 2

This function can be applied to the iterable values to get hash values.

# Python hash() function example
# Calling function
result = hash("javatpoint") # string value
result2 = hash((1,2,22)) # tuple value
# Displaying result
print(result)
print(result2)

Output:

-3147983207067150749
2528502973955190484

Python hash() Function Example 3

# Python hash() function example
# Calling function
result = hash("javatpoint") # string value
result2 = hash([1,2,22]) # list
# Displaying result
print(result)
print(result2)

Output:

TypeError: unhashable type: 'list'

Python hash() Function Example 4

Here, we are passing a new custom object to the function. The function returns the hash of this object.

# Python hash() function example
class Student:
    def __init__(self,name,email):
        self.name = name
        self.email = email
        
student = Student("Arun", "arun@abc.com")
# Calling function
result = hash(student) # object
# Displaying result
print(result)

Output: