If we have a function definition with no content, put in the pass statement to avoid getting an error.
def ourfunction():
pass
Python Recursion
In python a function can call itself.
Use: Looping
To be avoided while using recursion:
- Writing a never ending program.
- Writing a program which uses excessive power.
- Writing a program which uses excess memory.
Example
def recursion(m):
if(m > 0):
result = m + tri_recursion(m – 1)
print(result)
else:
result = 0
return result
print(“\n\nRecursion Example Results”)
recursion(6)
Return Values
A return value returns function value.
def Ten_function(x):
return 10 * x
print(Ten_function(3))
print(Ten_function(5))
print(Ten_function(9))
Passing a List as an Argument
We can send any data type as argument to a function (string, number, list, dictionary etc.), and it will be treated as the same data type inside the function.
E.g. if we send a List as an argument, it will still be a List when it reaches the function:
def cricket_team(teams):
for x in teams:
print(x)
players = [“rohit”, “kohli”, “bumrah”]
cricket_team(players)
Default Parameter Value
If we call a function without argument, it calls default value.
def our_function(state = “Karnataka”):
print(“I am from “ + state)
our_function(“Maharashtra”)
our_function(“Kerala”)
our_function()
our_function(“Telangana”)
Arbitrary Number of Keyword Arguments, **kwargs
Add two asterisks ** before arguments if number of keyword arguments is not known.
def my_optionals(**subject):
print(“His language optional is “ + subject[“lang”])
my_optionals(math = “algebra”, lang = “French”)
Keyword Arguments
Key, value pair arguments can be given to functions in python.
The order can be arbitrary.
def my_subjects(subject3, subject2, subject1):
print(“The first subject is “ + subject1)
my_subjects(subject1 = “English”, subject2 = “Kannada”, subject3 = “Hindi”)
Arbitrary Arguments (*args)
When in doubt about number of arguments, add * before the argument.
def world_cup(*teams):
print(“The World Cup teams are “ + teams[2])
world_cup(“India”, “South Africa”, “Australia”)
Number of Arguments to a function
A function must have as many arguments as defined. If the number of arguments is less or more it will give an error.
def name_function(firstname, lastname):
print(firstname + ” “ + lastname)
name_function(“Raj”, “Kumar”)
Arguments in Python
Arguments are passed inside parentheses.
def our_second_function(firstname):
print(firstname + “Raj”)
our_second_function(“Mohan”)
our_second_function(“Narasimha”)
our_second_function(“Krishna”)
There can be as many arguments as required, separated by a comma(,).