Python

Python Intermediate Functions

Python Intermediate Functions

This page covers the intermediate functions of Python programming.

For Python basic functions here.

It continues the previous basic tutorials in more details. Intermediate functions encompass:

  • keyword arguments
  • default parameters
  • “pass” statement
  • “return” function
  • “lambda” function

Keyword arguments

Through the use of parameters and arguments, functions can circulate a stream of information. Note that the number as well as order of parameters when creating the function must match the number of arguments when calling the function.

Keyword arguments can avoid the order issue (see below).

def person(name, surname):
    print("My name is " + name)
    print("And my surname is " + surname)

person(surname = "Smith", name = "John")
# Output:
My name is John
And my surname is Smith

Even though the surname is in the first position, keyword arguments help the function associate the right order.

Default parameters

The function default parameters set the standard value setting. This means that in the case of a missing argument value, the function will produce the default value.

The following is an example of a default parameter.

def person(name, surname = "Smith"):
    print("My name is " + name)
    print("And my surname is " + surname)

person("John")
# Output:
My name is John
And my surname is Smith

The default parameter sets the setting in the case of a missing argument value. But different values can pass even with a default parameter.

See below.

def person(name, surname = "Smith"):
    print("My name is " + name)
    print("And my surname is " + surname)

person("John", surname = "Williams")
# Output:
My name is John
And my surname is Williams

Note that default parameters always go at the end of the list. Therefore, non-default parameters must always be declared first, otherwise Python produces an error. 

def person(surname = "Smith", name):
    print("My name is " + name)
    print("And my surname is " + surname)

# Output: SyntaxError: non-default argument follows default argument

“Pass” statement

Functions cannot operate without any statements, as the program produces an error. The pass statement allows Python to process empty functions without issues.

The following is an example of an empty function.

def person():
    
# Output: IndentationError

The following is an example of a function with the “pass” statement.

def person():
    pass

# Output:

Return statement

The “return” statement inside a function produces (returns) a value. It is commonly used with mathematical expressions.

Below is an example of the function “return” statement.

def num(a, b):
    return 6 * a + (b / 2) 

num(2, 6)

# Output: 15.0

Lambda function

In Python, “lambda” functions are small (one line) methods. They can have only one output expression, but allow single or multiple arguments.

The keyword is “lambda“, followed by the argument(s), colon, and the expression.

# one argument
lambda argument : expression

# two arguments
lambda argument, argument : expression

The following is an example of one argument lambda.

num = lambda a: 5 * a

print(num(2))

# Output: 10

The following is an example of 3 arguments lambda.

num = lambda a, b, c: (a + b + c) / 2

print(num(4, 10, 8))

# Output: 11.0

Next: Python Intermediate Classes

Related Posts