Function
A function is a block of code which only runs when it is called. You can pass data in a function called parameter. In Python a function is defined using the def keyword.
Syntax:
def function_name():
Example:
def greeting():
print("Good Morning")
print("Good Evening")
print("Good Night")
greeting()
greeting()
Output :
Good Morning
Good Evening
Good Night
Good Morning
Good Evening
Good Night
Example Explanation :
In the above example, in 1st line we can create a function using def keyword. The name of that function is greeting(). In the 2nd, 3rd and 4th line we print message. In the 5th line we can called a function greeting().
Example :
def fun(val1):
print("input :",val1)
fun(10)
fun(20)
fun(30)
Output :
input : 10
input : 20
input : 30
Example Explanation :
In the above example, in 1st line we can create a function. The name of that function is fun then we can pass a parameter val1. In 2nd line we can print output. In 3rd line we can called a function and pass the parameter 10. In 4th line we can called a function and pass the parameter 20. In 4th line we can called a function and pass the parameter 30.
Write a program to find square of number using function.
def cal_square(num):
square = num * num
print("Square :",square)
cal_square(10)
cal_square(25)
Output :
Square : 100 Square : 625
Example Explanation :
In the above example, in 1st line we can create a function. The name of that function is cal_square then we can pass a parameter num. In the 2nd line we create a variable. The name of that variable is sq in that sq function we can stored the multiplication of number. In 3rd line we can print the output. In the 4th and 5th line we can called a function and pass the parameter 10 and 25.
Return Values:
To return a value from a function by using the return statement.
Example :
def cal_square(num):
sq = num * num
return sq
ans = cal_square(5)
print(ans)
Output :
25
Example Explanation :
In the above example, we can create a function. The name of that function is cal_square. In the 2nd line we create a variable. The name of that variable is sq in that sq function we can stored the multiplication of number. In the 3rd line we used return statment. That return statment return a square of number to the cal-square function. In the 4th line we create a variable the name of that variable is ans. In ans variable we can called a function and pass the parameter 5. In the 5th line we can print ans.
Take input from user
Example :
def cal_square():
num = int (input("Enter num: "))
sq = num * num
return sq
ans = cal_square()
print(ans)
Output :
Enter num: 20 400
Example Explanation :
In the above example, we can create a function. The name of that function is cal_square. In the 2nd line we can create a variable num. In that variable we take a input from user. In the 3rd line we create a variable. The name of that variable is sq in that sq function we can stored the multiplication of number. In the 4th line we used return statment. That return statment return a square of number to the cal-square function. In the 5th line we can create a variable the name of that variable is ans. In ans variable we can called a function and pass the parameter 5. In the 6th line we can print ans.
Example :
def add_two(num1, num2):
sum = num1 + num2
print(sum)
add_two(10,20)
Output :
30
In the above example, in 1st line we can create a function. The name of that function is add_two. In the 2nd line we can create variable sum. In that variable we stored a addition of two numbers. In the 3rd line print a sum. In the 4th line we can called a function and pass the parameter 10 and 20.
Simple Interest
Write a program to find simple interest using function all cases .
💡 HINT : Simple Interest = (P x T x R)/100 Where, P is the principle amount T is the time and R is the rate
👉Answer Of this program based on following 4 ways:
1. No Arguments And No Return:
Program :
def cal_si():
p = int(input("Enter Principle : "))
r = int(input("Enter Rate : "))
t = int(input("Enter time : "))
si = p*r*t/100
print(si)
cal_si()
Output
Enter Principle : 5000
Enter Rate : 3
Enter time : 2
300.0
In the above example, we create one function that's name is cal_si in that function we are create three variables and taking input from user for p for amount, r for rate, t for time & isi in last storing value of this variables in the si variable and print variable.
2. Arguments but No Return:
Program :
def cal_si(p,r,t):
si = p*r*t/100
print(si)
Amount = int(input("Enter Amount : "))
Rate = int(input("Enter Rate : "))
Time = int(input("Enter Time : "))
cal_si(Amount, Rate, Time)
Output
Enter Principle : 5000
Enter Rate : 3
Enter time : 2
300.0
In the above example, we are we are create cal_si function in that function pass three parameter p, r and t . we are crete three variable also name are Amount,Rate & time in that variable input taking from users, and storing their value in variable that's variable name is si . when we are call cal_si function in their function pass three parameter values. ie Amount,Rate & time .
3. No Arguments but Return:
Program :
def cal_si():
p = int(input("Enter Principle : "))
r = int(input("Enter Rate : "))
t = int(input("Enter time : "))
si = p*r*t/100
return si
ans = cal_si()
print(ans)
Output
Enter Principle : 5000
Enter Rate : 3
Enter time : 2
300.0
In the above example, we create one function that's name is cal_si in that function we are create three variables and taking input from user for p for amount, r for rate, t for time & si in last storing value of this variables in the si variable and return si. this si value stored in cal_si function so, we are storing this value in ans variable then in last print ans variable.
4. Arguments And Return:
Program :
def cal_si(p, r, t):
si = p*r*t/100
return si
Amount = int(input("Enter Amount : "))
Rate = int(input("Enter Rate : "))
Time = int(input("Enter Time : "))
ans = cal_si(Amount,Rate, Time)
print(ans)
Output
Enter Principle : 5000
Enter Rate : 3
Enter time : 2
300.0
In the above example, we are create cal_si function in that function pass three parameter p, r and t . we are crete three variable also name are Amount,Rate & time in that variable input taking from users, and storing their value in variable that's variable name is si . then return si variable, this si value stored in cal_si function so, we are storing this value in ans variable in that fuction pass three parameter Amount, Rate & Time then in last print ans variable .
num = int(input("How many times do you want to print :"))
f = 0
s = 1
print(f)
print(s)
for i in range(num):
num = f + s
f = s
s = num
print(num)
Output
How many times do you want to print :5
0
1
1
2
3
5
8
In the above example, we are taking create one variable that is num and taking input from the user. In the f variable we are storing value of 0 and s variable we are storing value of 1 then print f & s. The for statement initiates a loop that will repeat for a specified number of times, in this case, num times.
then we are creating num variable and in this variable storing value of addtion of f & s. In this f variable we are storing value of s. and s variable storing value of num then print this num variable.
def add_two(num1, num2):
sum = num1 + num2
print(sum)
add_two(10,20)
Output
30
In the above example, we are create add_twofunction. in this function we are pass two parameter num1 & num2. In this function we are create a one variable sum that variable num1 + num2. When we are defined function add_two with the parameter 10 & 20.
def add_two(num1, num2):
sum = num1 + num2
sub = num1-num2
return sum, sub
a, b = add_two(20, 10)
print(a)
print(b)
Output
30
10