Lambda functions in python
Lambda function is a pre-existing or reserved keyword in Python programming. Which is defined by the programmer as anonymous function or lambda expression in Python, Lambda function is a process of creating small and temporary manual lambda function in Python programming. In Python program, programmers can define and manipulate custom lambda function using reserved lambda keyword.
So let’s know the lambda function syntax in Python programming.
Python Lambda Argument : lambda Expression
Remember that in the declared lambda function in Python program, any number of arguments can be developed or created as per the programming requirement, but only one lambda program expression can be defined in the program. According to the Python program, when the lambda function is called in the program, the detailed evolution of the given lambda expression takes place, and according to the lambda expression the output of the value is returned in the program.
Lambda expression syntax and examples in Python.
Here are some examples of lambda functions in simple Python programs.
Lambda function with single argument in Python.
squarert = lambda p: p ** 2 # create a lambda function expression
print(“\n the lambda squareroot is -“,squarert(9)) # the result is – 81
In the above lambda function example.
The expression lambda p: p ** 2 is a custom user created lambda function in Python program. It holds a lambda argument variable value p, and returns the output value p ** 2 in the lambda expression.
Where squarert is a user defined Python program variable. It performs the lambda function in this program, and calling squarert(9) calculates and displays the square root value of 81.
Lambda function example with multiple arguments in Python program.
join = lambda p, q: p + q
print(“\n The join of two integers is -“,join(5, 6)) # the result is – 11
In the above lambda expression, where lambda p, q: p + q is a lambda function created with two Python program lambda variable arguments p and q which adds both the values when called with join(5, 6) along with the value of p and q arguments.
lambda function without arguments in Python program.
vcanhelpsu = lambda: “welcome to, Lambda function”
print(vcanhelpsu()) # the result is – welcome to, lambda function
In the above lambda expression the lambda function does not hold any argument variables and only returns the output of the user defined “welcome to, Lambda function” string value.
Using Lambda Function in Python Program.
Lambda functions are often used in Python programs in conditions where a small function needs to be created temporarily,
such as in Python programs,
Python sorting: Lambda function as sorting operation.
integer = [(0, 3), (1, 2), (5, 3)]
integer_arrange = sorted(integer, key=lambda integer: integer[0])
print(“\n the arrange integer order is -“,integer_arrange) # the result is – [(1, 2), (0, 3), (5, 3)]
Lambda function filtering: Lambda as predicate function in filter operation.
integer = [1, 2, 3, 4, 5, 6, 7, 8, 9, 11, 12, 13]
odd_integer = list(filter(lambda p: p % 2 == 1, integer))
print(“\n list of odd integer is -“,odd_integer) # the result is – [1, 3, 5, 7, 9, 11, 13]
Python lambda mapping: transformations in map operation.
integer = [1, 2, 3, 4, 5, 6, 7]
squart_integer = list(map(lambda p: p ** 2, integer))
print(“\n the square root of given number is -“, squart_integer) # the result is – [1, 4, 9, 16, 25, 36, 49]
Python Lambda Reduce: Combine functions in reduce operation.
from functools import reduce # import reduce package library
multiply = reduce(lambda p, q: p * q, [1, 2, 3, 4, 5])
print(“\n the multiply of all number is -“,multiply) # the result is – 120
Limitations of Lambda function in Python language.
Lambda functions in Python programs are limited to a single expression, and programming conditional statements like print, if, else, for, etc. are not fully supported in Lambda functions. Lambda expressions are dedicated to simple program operation, where a complete function is declared using def keyword in Python programs.
Lambda Detail Analysis.
In the beginning of Lambda function, we learned that Lambda function in Python program is a small user created function, which provides a feature to create anonymous function. But in some cases Lambda functions can be powerful and more useful, but you have to use Lambda function carefully in Python program and manage Lambda function operation.
