Day 21 - Function Arguments and Statements
There are four types of arguments that we can provide in a function:
Default Arguments
Keyword Arguments
Variable length Arguments
Required Arguments
1. Default arguments:
We can provide a default value while creating a function. This way the function assumes a default value even if a value is not provided in the function call for that argument.
Example 1 :
def average(a=9, b=1): #default arguments
print("The average is ", (a+b)/2)
average()
Output:
The average is 5.0
\=========================================================
Example 2 :
def average(a=9, b=1): #default arguments
print("The average is ", (a+b)/2)
average(1,5) #it ignores above values and take a=1 and b=5
Output:
The average is 3.0
\=========================================================
Example 3 :
def average(a=9, b=1): #default arguments
print("The average is ", (a+b)/2)
average(5) #here only value of a is given so a=5 and b=1 (i.e. deafult value given above)
Output:
The average is 3.0
\=========================================================
Example 4 :
def average(a=9, b=1): #default arguments
print("The average is ", (a+b)/2)
average(b=9) #here only value of b is given so b=9 and a=9 (i.e. deafult value given above)
Output:
The average is 9.0
\=========================================================
Example 5 :
def name(fname, mname = "Jhon", lname = "Whatson"):
print("Hello,", fname, mname, lname)
name("Amy")
Output:
Hello, Amy Jhon Whatson
2. Keyword arguments:
We can provide arguments with key = value, this way the interpreter recognizes the arguments by the parameter name. Hence, the the order in which the arguments are passed does not matter.
Example 1 :
def average(a=9, b=1): #keyword arguments
print("The average is ", (a+b)/2)
average(b=9, a=21) #here order of value doesnot matters
Output:
The average is 15.0
\=========================================================
Example 2 :
def name(fname, mname, lname):
print("Hello,", fname, mname, lname)
name(mname = "Peter", lname = "Wesker", fname = "Jade")
Output:
Hello, Jade Peter Wesker
3. Required arguments:
In case we don’t pass the arguments with a key = value syntax, then it is necessary to pass the arguments in the correct positional order and the number of arguments passed should match with actual function definition.
Example 1:
def average(a, b, c=1): #required arguments
print("The average is ", (a + b + c) / 2)
average(5,6)
#In above function value of a and b is not given, so we have given there values here a=5, b=6 and c=1 (default value given above)
Output:
The average is 6.0
\=========================================================
Example 2:
def average(a, b): #required arguments
print("The average is ", (a+b)/2)
average(4, 6)
Output:
The average is 5.0
\=========================================================
Example 3:
def name(fname, mname, lname):
print("Hello,", fname, mname, lname)
name("Peter", "Ego", "Quill")
Output:
Hello, Peter Ego Quill
4. Variable-length arguments:
Sometimes we may need to pass more arguments than those defined in the actual function. This can be done using variable-length arguments.
There are two ways to achieve this:
Arbitrary Arguments
Keyword Arbitrary Arguments
Arbitrary Arguments:
While creating a function, pass a * before the parameter name while defining the function. The function accesses the arguments by processing them in the form of tuple.
Example 01 :
def average(*numbers):
#print(type(number)) # tuple - it takes input as tuple/list.
sum = 0 #initialize
for i in numbers:
sum = sum + i
print("Average is: ", sum/len(numbers))
#average(5,6) #output: Average is: 5.5
average(5, 6, 7, 1) #output: Average is: 4.5
#with the help of above function, we can take average of as many numbers as we want
Output:
Average is: 4.5
\======================================================== Example 02 :
def name(*name):
print("Hello,", name[0], name[1], name[2])
name("James", "Buchanan", "Barnes")
Output:
Hello, James Buchanan Barnes
Keyword Arbitrary Arguments:
While creating a function, pass a * before the parameter name while defining the function. The function accesses the arguments by processing them in the form of dictionary.
Example 01 :
def name(**name):
#print(type(number)) # dictionary - it takes input as dictionary.
print("Hello,", name["fname"], name["mname"], name["lname"])
name(mname = "Buchanan", lname = "Barnes", fname = "James")
Output:
Hello, James Buchanan Barnes
return Statement
The return statement is used to return the value of the expression back to the calling function.
Example 01 :
def average(*numbers):
sum = 0 #initialize
for i in numbers:
sum = sum + i
return sum/len(numbers)
c = average(5, 6, 7, 1)
print(c) #return function stores value and save it in varaible
Output:
4.75
\======================================================== Example 02 :
def average(*numbers):
sum = 0 #initialize
for i in numbers:
sum = sum + i
return 7 #If we use use more thane one return statement, then jo bhi pehley return mileyga, yeh return statement ussy return kareygi.
return sum/len(numbers)
c = average(5, 6, 7, 1)
print(c) #return function stores value and save it in varaible
Output:
7
\======================================================== Example 03 :
def name(fname, mname, lname):
return "Hello, " + fname + " " + mname + " " + lname
print(name("James", "Buchanan", "Barnes"))
Output:
Hello, James Buchanan Barnes
