Chapter 10: Functions

Example 10.1, Page number: 320

In [1]:
#user defined function

import sys

#Variable Initialization
x = 1
y = 2

#Function definition
def add(a,b):
    return a+b

#Function call
z = add(x,y)

#Result
sys.stdout.write("z = %d"%(z))

z = 3

Example 10.2, Page number: 321

In [2]:
#Call user-defined function at different places.

import sys

#Function definitions
def y():
    sys.stdout.write(" Y")
    return

def a():
    sys.stdout.write(" A")
    y()
    return

def b():
    sys.stdout.write(" B")
    a()
    return

def c():
    a()
    b()
    sys.stdout.write(" C")
    return

def d():
    sys.stdout.write(" D")
    c()
    b()
    a()
    return

#Function calls
y()
a()
b()
c()
d()

 Y A Y B A Y A Y B A Y C D A Y B A Y C B A Y A Y

Example 10.3, Page number: 323

In [3]:
#Using similar variable names in different functions.

import sys

#Function definition
def fun():
    b = 20
    c = 10
    sys.stdout.write("\nIn fun() B = %d  C = %d"%(b,c))
    return

#Variable Initialization
b = 10
c = 5

#Result
sys.stdout.write("\nIn main() B = %d  C = %d"%(b,c))
fun()

In main() B = 10  C = 5
In fun() B = 20  C = 10

Example 10.4, Page number: 323

In [6]:
#Global variables on different functions.

import sys

#Global Variable Initialization
b = 10
c = 5

def fun():
    global b 
    b += 1
    global c 
    c -= 1
    sys.stdout.write("\nIn fun() B = %d  C = %d"%(b,c))
    return

#Result
sys.stdout.write("\nIn main() B = %d  C = %d"%(b,c))
fun()
b += 1
c -= 1
sys.stdout.write("\nAgain In main() B = %d C = %d"%(b,c))

In main() B = 10  C = 5
In fun() B = 11  C = 4
Again In main() B = 12 C = 3

Example 10.5, Page number: 325

In [1]:
#Using return statement in different ways

import sys

#Function definition
def pass1(a):
    if a == 0:
        return;
    else:
        return a*a*a

#Variable Initialization
x = int(raw_input("Enter value of x : "))

#Function call & Result
if x != 1 or x > 0:
    y = pass1(x)

#There is no switch statement in python, so if..else statement
if y == 1:
    sys.stdout.write("The value returned is %d"%(y))
else:
    sys.stdout.write("The Cube of %d is : %d"%(x,y))
    

Enter value of x : 5
The Cube of 5 is : 125

Example 10.6, Page number: 327

In [4]:
#Display message using user defined function

import sys

#Function definition
def message():
    sys.stdout.write("Have a nice day")

#function call
message()

Have a nice day

Example 10.7, Page number: 328

In [5]:
#Display Alphabets 'A','B' and 'C' using functions

import sys

#Functions definitions
def a():
    sys.stdout.write("\nA")
    
def b():
    sys.stdout.write(" B")
    
def c():
    sys.stdout.write(" C")
    
#Function call
a()
b()
c()

A B C

Example 10.8, Page number: 329

In [2]:
#Send value to user defined function and display results

import sys

#Function Definition
def dat(x,y,z):
    sys.stdout.write("Date = %d/%d/%d"%(x,y,z))
    
#Variable Initialization
d = int(raw_input("Enter date dd/mm/yy"))
m = int(raw_input("Enter date dd/mm/yy"))
y = int(raw_input("Enter date dd/mm/yy"))

#function call & Result
dat(d,m,y)

Enter date dd/mm/yy12
Enter date dd/mm/yy12
Enter date dd/mm/yy2001
Date = 12/12/2001

Example 10.9, Page number: 330

In [7]:
#Square of number using user defined function

import sys

#function definition
def sqr(k):
    sys.stdout.write("\n%d"%(k*k))
    
#Variable Initialization
j = 0

#Function call & Result
for j in range(1,5):
    sqr(j)

1
4
9
16

Example 10.10, Page number: 330

In [3]:
#Pass the value to main() function

import sys

#There is no main function in python
sys.stdout.write("\nNumber of command line arguments J = %d"%(len(sys.argv)))

Number of command line arguments J = 6

Example 10.11, Page number: 331

In [3]:
#Pass and return values to user defined function.  

import sys

#Function Definitions
def dat(x,y,z):
    sys.stdout.write("\nToday = %d/%d/%d"%(x,y,z))
    x += 1
    return x

#Variable Initialization
d = int(raw_input("Enter Date dd/mm/yy : "))
m = int(raw_input("Enter Date dd/mm/yy : "))
y = int(raw_input("Enter Date dd/mm/yy : "))

#Function call
t = dat(d,m,y)

#Result
sys.stdout.write("\nTomorrow = %d/%d/%d"%(t,m,y))

Enter Date dd/mm/yy : 12
Enter Date dd/mm/yy : 12
Enter Date dd/mm/yy : 2001

Today = 12/12/2001
Tomorrow = 13/12/2001

Example 10.12, Page number: 332

In [4]:
#Send and recieve values to user defined function 

import sys

#Function definition
def sum1(x,y,z):
    return x+y+z

#Variable Initialization
a = int(raw_input("Enter Three Numbers : "))
b = int(raw_input("Enter Three Numbers : "))
c = int(raw_input("Enter Three Numbers : "))

#Function call
s = sum1(a,b,c)

#Result
sys.stdout.write("Sum = %d"%(s))

Enter Three Numbers : 7
Enter Three Numbers : 5
Enter Three Numbers : 4
Sum = 16

Example 10.13, Page number: 333

In [5]:
#Recieve values from user defined function without passing any 
#value through main().

import sys

#Function definition
def sum1():
    x = int(raw_input("Enter Three Numbers : "))
    y = int(raw_input("Enter Three Numbers : "))
    z = int(raw_input("Enter Three Numbers : "))
    return x+y+z

#Function call
s = sum1()

#Result
sys.stdout.write("Sum = %d"%(s))

Enter Three Numbers : 3
Enter Three Numbers : 5
Enter Three Numbers : 4
Sum = 12

Example 10.14, Page number: 333

In [6]:
#Return value in the form of address.

import sys

#Function definition
def sum1():
    x = int(raw_input("Enter Three Values : "))
    y = int(raw_input("Enter Three Values : "))
    z = int(raw_input("Enter Three Values : "))
    k = x + y + z
    return k

#There is no pointer concept in python

#Function call
s = sum1()

#Result
sys.stdout.write("Sum = %d"%(s))

Enter Three Values : 3
Enter Three Values : 5
Enter Three Values : 4
Sum = 12

Example 10.15, Page number: 334

In [7]:
#Call by value

import sys

#Function Definition
def change(a,b):
    k = a
    a = b
    b = k
    sys.stdout.write("\nIn Change() X = %d Y = %d"%(a,b))
    
#Variable Initialization
x = int(raw_input("Enter Values of X & Y : "))
y = int(raw_input("Enter Values of X & Y : "))

#Function call
change(x,y)

#Result
sys.stdout.write("\nIn main() X = %d Y = %d"%(x,y))

Enter Values of X & Y : 5
Enter Values of X & Y : 4

In Change() X = 4 Y = 5
In main() X = 5 Y = 4

Example 10.16, Page number: 335

In [8]:
#Call by reference 

import sys

#Function Definition
def change(a,b):
    k = a
    a = b
    b = k
    sys.stdout.write("\nIn Change() X = %d Y = %d"%(a,b))
    
#There is no pointer concept in python

#Variable Initialization
x = int(raw_input("Enter Values of X & Y : "))
y = int(raw_input("Enter Values of X & Y : "))

#Function call
change(x,y)

#Result
sys.stdout.write("\nIn main() X = %d Y = %d"%(y,x))

Enter Values of X & Y : 5
Enter Values of X & Y : 4

In Change() X = 4 Y = 5
In main() X = 4 Y = 5

Example 10.17, Page number: 336

In [9]:
#Return by reference

import sys

#Function Definition
def change(a,b):
    c = a + b
    d = a - b
    return c,d

#Variable Initialization
x = int(raw_input("Enter Values of X & Y : "))
y = int(raw_input("Enter Values of X & Y : "))

#Function call
add,sub = change(x,y)

#Result
sys.stdout.write("\nAddition : %d"%(add))
sys.stdout.write("\nSubtraction : %d"%(sub))

Enter Values of X & Y : 5
Enter Values of X & Y : 4

Addition : 9
Subtraction : 1

Example 10.18, Page number: 337

In [15]:
#Call by value and reference

k = 0
m = 0

#Function Definition
def other(k,m):
    sys.stdout.write("\nAddress of k & m in other() : %u %u"%(id(k),id(m)))
    
#Result
sys.stdout.write("\nAddress of k & m in main() : %u %u"%(id(k),id(m)))

#Function call
other(k,m)

#there is no pointer concept in python and it uses value tagged method in data storage
#instead of addressing the memory location, values of same variables are tagged together

Address of k & m in main() : 30922996 30922996
Address of k & m in other() : 30922996 30922996

Example 10.19, Page number: 338

In [17]:
#User defined function as an argument to another function.

#Variable Initialization
y = 2

#Function Definitions
def double(m):
    return m*2

def square(k):
    return k*k

#Function call
x = double(square(y))

#Result
sys.stdout.write("x = %d"%(x))

x = 8

Example 10.20, Page number: 338

In [10]:
#Two functions as arguments for another functions

import sys

#Function definitions
def x(a,b):
    return abs(a-b)

def y():
    y = int(raw_input("Enter First Number : "))
    return y

def z():
    z = int(raw_input("Enter Second Number : "))
    return z

#Function call
d = x(y(),z())

#Result
sys.stdout.write("\nz() - y() = %d"%(d))

Enter First Number : 25
Enter Second Number : 50

z() - y() = 25

Example 10.21, Page number: 339

In [11]:
#Return only absolute value like abs() function

import sys

#Function Definition
def uabs(y):
    if y < 0:
        return y * -1
    else:
        return y
    
#Variable Initialization
x = int(raw_input("Enter a Negative Value : "))

#Function call
x = uabs(x)

#Result
sys.stdout.write("\nX = %d"%(x))

Enter a Negative Value : -5

X = 5

Example 10.22, Page number: 340

In [12]:
#Square and cube of an entered number.  

import sys

#Function Definitions
def input1():        #Since input() is a built in function in python, input1() is used
    k = int(raw_input("Number : "))
    return k

def sqr(m):
    sys.stdout.write("\nSquare : %d"%(m*m))
    return m

def cube(m):
    return m*m*m

#Function call and Result
sys.stdout.write("\nCube : %d"%(cube(sqr(input1()))))

Number : 2

Square : 4
Cube : 8

Example 10.23, Page number: 341

In [13]:
#Assign return value of a function to variable.

import sys

#Function Definition
def input1():
    k = int(raw_input("Enter Value of x = "))
    return k

#Function call
x = input1()

#Result
sys.stdout.write("\nx = %d"%(x))

Enter Value of x = 5

x = 5

Example 10.24, Page number: 342

In [14]:
#Addition and subtraction of numbers with return value of function.

import sys

#Function Definition
def input1():
    k = int(raw_input("Enter Value of x = "))
    return k

def sqr(m):
    return pow(m,2)

#Function call
x = sqr(1 - input1() + 1)

#Result
sys.stdout.write("\nSquare = %d"%(x))

Enter Value of x = 5

Square = 9

Example 10.25, Page number: 343

In [15]:
#Multiplication and division of numbers with return value of function.

import sys

#Function Definition
def input1():
    k = int(raw_input("Enter Value of x = "))
    return k

def sqr(m):
    return pow(m,2)

#Function call
x = sqr(5 * input1()/2)

#Result
sys.stdout.write("\nSquare = %d"%(x))

Enter Value of x = 5

Square = 144

Example 10.26, Page number: 344

In [16]:
# ++ operator with return value of function

import sys

#Function Definition
def input1():
    k = int(raw_input("Enter Value of x = "))
    return k

def sqr(m):
    return pow(m,2)

#Function call
#There is no ++ operator in python. so += operator is used
y = input1()
y += 1
x = sqr(y)

#Result
sys.stdout.write("\nSquare = %d"%(x))

Enter Value of x = 7

Square = 64

Example 10.27, Page number: 345

In [17]:
#Use mod(%) with function

import sys

#Function Definition
def j():
    x = int(raw_input("Enter a Number : "))
    return x
    
#Function call & Result
if j() %2 == 0:
    sys.stdout.write("\nNumber is Even.")
else:
    sys.stdout.write("\nNumber is Odd.")

Enter a Number : 5

Number is Odd.

Example 10.28, Page number: 346

In [18]:
#Conditional operator(?) with function.

import sys

#Function Definitions
def sqr(x):
    sys.stdout.write("Square ")
    return pow(x,2)

def cube(x):
    sys.stdout.write("Cube ")
    return pow(x,3)

def y():
    return 10

#Variable Initialization
x = int(raw_input("Enter a Number : "))

#Function call
z = sqr(x) if x > y() else cube(x)

#Result
sys.stdout.write(" = %d"%(z))

Enter a Number : 5
Cube  = 125

Example 10.29, Page number: 346

In [19]:
#compare two return values of functions

import sys

#Function Definitions
def a():
    x = int(raw_input("Enter a Number a() : "))
    return x

def b():
    x = int(raw_input("Enter a Number b() : "))
    return x

#Function call and Result
if a() == b():
    sys.stdout.write("\nValue of a() & b() are equal")
else:
    sys.stdout.write("\nValue of a() & b() are unique")

Enter a Number a() : 5
Enter a Number b() : 5

Value of a() & b() are equal

Example 10.30, Page number: 347

In [20]:
#Evaluate the equation s = sqr(a() + b()) using function

import sys

#Function Definitions
def a():
    a = int(raw_input("Enter value of a : "))
    return a

def b():
    b = int(raw_input("Enter value of b : "))
    return b

def sqr(x):
    return x*x

#Function call
s = sqr(a() + b())

#Result
sys.stdout.write("\nSquare of Sum = %d"%(s))

Enter value of a : 5
Enter value of b : 3

Square of Sum = 64

Example 10.31, Page number: 348

In [21]:
#Evaluate the equation y = x^1+x^2..x^n using function

import sys

#Function Definition
def b(m):
    m += 1
    #sys.stdout.write("%d"%(m))
    return m

#Variable Initialization
x = int(raw_input("Values of 'x' and 'n' : "))
n = int(raw_input("Values of 'x' and 'n' : "))
y = 0
z = 1
m = 0

while(z <= n):
    m = b(m)
    y = y + pow(x,m)
    sys.stdout.write("%d + "%(y))
    z += 1
    
if z >= n:
    sys.stdout.write("\nValue of y = %d"%(y))

Values of 'x' and 'n' : 3
Values of 'x' and 'n' : 3
3 + 12 + 39 + 
Value of y = 39

Example 10.32, Page number: 350

In [22]:
#Call user defined function through if statement

import sys

#Function Definition
def a():
    a = int(raw_input("Enter value of a :"))
    return a

#Function call and Result
if a()%2 == 0:
    sys.stdout.write("\nThe number is even.")
else:
    sys.stdout.write("\nThe number is odd.")

Enter value of a :5

The number is odd.

Example 10.33, Page number: 351

In [23]:
#Call user defined function through switch() statement

import sys

#Function Definition
def a():
    c = raw_input("Enter Your Choice Square(s), Cube(c), Double(d) : ")
    c = c.lower()
    return c

#Variable Initialization
x = 5

#There is no switch() statement in python.
c = a()
if c == 's':
    sys.stdout.write("\nSquare of %d is %d"%(x,pow(x,2)))
else:
    if c == 'c':
        sys.stdout.write("\nCube of %d is %d"%(x,pow(x,3)))
    else:
        if c == 'd':
            sys.stdout.write("\nDouble of %d is %d"%(x,x*2))
        else:
            sys.stdout.write("\nUnexpected Choice printed as it is : %d"%(x))
         

Enter Your Choice Square(s), Cube(c), Double(d) : D

Double of 5 is 10

Example 10.34, Page number: 353

In [14]:
#Call function through the for loop

import sys

#Function Definition
def plus(k):
    if k == 10:
        return 0
    else:
        return k
    
#Variable Initialization
m = 1

#Function call & Result
#in python, for loop iterates through a range of number. so while loop is used instead.
while plus(m) != 0:
    sys.stdout.write("%3d"%(m))
    m += 1
    

  1  2  3  4  5  6  7  8  9

Example 10.35, Page number: 354

In [25]:
#Call user defined function through while() loop

import sys

#Function Definition
def y():
    x = int(raw_input("Enter a Number : "))
    return x

#Function call & Result
while y() != 0:
    sys.stdout.write("Value enter is non-zero\n")

Enter a Number : 5
Value enter is non-zero
Enter a Number : 0

Example 10.36, Page number: 355

In [27]:
#Call user defined function through do while() loop

import sys

#Function Definition
def y():
    x = int(raw_input("Enter a Number : "))
    return x

#Function call and Result
#There is no do-while loop in python

while y() != 0:
    sys.stdout.write("\nValue entered is non-zero\n")

Enter a Number : 5

Value entered is non-zero
Enter a Number : 0

Example 10.37, Page number: 356

In [28]:
#Initialize an array using functions.

import sys

#Function Definition
def c(m):
    n = int(raw_input("Enter Number d[%d]"%(m+1)))
    return n

#Variable Initialization
d = [c(i) for i in range(0,5)]

sys.stdout.write("\nArray d[] elements are : ")
for k in range(0,5):
    sys.stdout.write("%2d"%d[k])

Enter Number d[1]4
Enter Number d[2]5
Enter Number d[3]6
Enter Number d[4]7
Enter Number d[5]8

Array d[] elements are :  4 5 6 7 8

Example 10.38, Page number: 357

In [20]:
#Pass array element to the function using call by value method.

import sys

#Function Definition
def show(m,u):
    sys.stdout.write("\nnum[%d] = %d"%(m+1,u))
    
#Variable initialization
num = [12,13,14,15,16,17,18]

#Function call & Result
for k in range(0,7):
    show(k,num[k])

num[1] = 12
num[2] = 13
num[3] = 14
num[4] = 15
num[5] = 16
num[6] = 17
num[7] = 18

Example 10.39, Page number: 358

In [22]:
#Pass array element to the function using call by reference

import sys

#Function Definition
def show(u):
    m = 0
    sys.stdout.write("\nnum[7] = {")
    while m != 7:
        #There is no pointer concept in python
        sys.stdout.write("%2d,"%(u[m]))
        m += 1
    sys.stdout.write("\b}")
    
#Variable Initialization
num = [12,13,14,15,16,17,18]

#Function call
show(num)

num[7] = {12,13,14,15,16,17,18,}

Example 10.40, Page number: 359

In [23]:
#Array elements in reverse order.

import sys

#Function Definition
def show(u):
    m = 6
    while m != -1:
        sys.stdout.write("\nnum[%d] = %d"%(m,u[m]))
        m -= 1
        
#Variable Initialization
num = [12,13,14,15,16,17,18]

#Function call
#There is no pointer concept in python
show(num)

num[6] = 18
num[5] = 17
num[4] = 16
num[3] = 15
num[2] = 14
num[1] = 13
num[0] = 12

Example 10.41, Page number: 360

In [24]:
#Copy array elements using user defined function.

import sys

#Function Definition
def cpy(p,m):
    j = 0
    while j != 5:
        m[j] = p[j]
        j += 1
        
#Variable Initialization
a1 = [1,2,3,4,5]
a2 = [0 for i in range(0,5)]

#Function call
cpy(a1,a2)

#Result
sys.stdout.write("Source  Target")
for h in range(0,5):
    sys.stdout.write("\n%5d\t%d"%(a1[h],a2[h]))

Source  Target
    1	1
    2	2
    3	3
    4	4
    5	5

Example 10.42, Page number: 361

In [29]:
#Read array of other function in main()

import sys

#Function definition
def arry(k):
    b = [1,2,3,4,5]
    return b[k]

#main() function
for k in range(0,5):
    sys.stdout.write("\t%d"%(arry(k)))

	1	2	3	4	5

Example 10.43, Page number: 361

In [30]:
#Interchange array elements of two arrays using function.

import sys
global a
global b

#Function Definitions
def read():
    x = int(raw_input(""))
    return x

def change(a,b):
#Since there is no pointer concept in python, exchange is done in the function using global variables.
    for x in range(0,5):
        a[x] = a[x] + b[x]
        b[x] = a[x] - b[x]
        a[x] = a[x] - b[x]
    
#Variable Initialization
a = [0 for i in range(0,5)]
b = [0 for i in range(0,5)]

for x in range(0,10):
    if x < 5:
        a[x] = read()
    else:
        b[x-5] = read()

#Swapping and Result
sys.stdout.write("\nArray A & B ")

for x in range(0,5):
    sys.stdout.write("\n%7d%8d"%(a[x],b[x]))
  
#There is no pointer concept in python.
change(a,b)
    
sys.stdout.write("\nNow A  & B")
for x in range(0,5):
    sys.stdout.write("\n%7d%8d"%(a[x],b[x]))

1
2
3
4
5
6
7
8
9
0

Array A & B 
      1       6
      2       7
      3       8
      4       9
      5       0
Now A  & B
      6       1
      7       2
      8       3
      9       4
      0       5

Example 10.44, Page number: 363

In [30]:
#Read array elements declared in different functions using global
#pointer declaration

import sys

#Function Definition
def call(j):
    m = 0
    u = [5,1,6,0,6]
    q = u
    while m != j:
        sys.stdout.write("%3d"%(u[m]))
        m += 1
    sys.stdout.write("\n")
    
#Variable Initialization
m = 0
k = [3,8,5,2,5]
q = k



#Result
while m != 5:
    sys.stdout.write("%3d"%(q[m]))
    m += 1

sys.stdout.write("\n")
call(5)

  3  8  5  2  5
  5  1  6  0  6

Example 10.45, Page number: 364

In [7]:
#Sum of 1 to 5 numbers using recursion

import sys
global s

s = 0
#Function definition
def main(x,s):
    s = s + x
    sys.stdout.write("\nx = %d s = %d"%(x,s))
    if x == 5:
        return
    x += 1
    main(x,s)
    
main(1,s)

x = 1 s = 1
x = 2 s = 3
x = 3 s = 6
x = 4 s = 10
x = 5 s = 15

Example 10.46, Page number: 365

In [31]:
#Calculate triangular number of a given number with recursion function method

import sys

#Function definition
def tri_num(m):
    f = 0
    if m == 0:
        return f
    else:
        f = f + m + tri_num(m-1)
        return f

#Variable Initialization
n = int(raw_input("Enter a Number : "))

#Function call
t = tri_num(n)

#Result
sys.stdout.write("\nTriangular number of %d is %d"%(n,t))
    

Enter a Number : 5

Triangular number of 5 is 15

Example 10.47, Page number: 366

In [47]:
#Display the given string using recursion

import sys
import os
global x

#Variable Initialization
x = 0
str1 = "Have a Good Day"

#Function Definition
def main(x):
    if x == len(str1):        #There is no null terminating character in python string
        return
    else:
        if str1[x] == 'H':
            os.system('cls')
            sys.stdout.write("%c"%(str1[x]))
        else:
            sys.stdout.write("%c"%(str1[x]))
    x += 1
    main(x)
    
#Function call
main(x)

Have a Good Day

Example 10.48, Page number: 367

In [51]:
#Display the given string 10 times using recursion

import sys
import os

#Function definition
def main(x):
    sys.stdout.write("\n%.2d] %s"%(x,str1))
    x += 1
    if x == 11:
        return
    else:
        if x == 1:
            os.system('cls')
            main(x)
        else:
            main(x)
            
            
#Variable Initialization
x = 0
str1 = "Have a Good Day"

#Function call
main(x)

00] Have a Good Day
01] Have a Good Day
02] Have a Good Day
03] Have a Good Day
04] Have a Good Day
05] Have a Good Day
06] Have a Good Day
07] Have a Good Day
08] Have a Good Day
09] Have a Good Day
10] Have a Good Day

Example 10.49, Page number: 368

In [32]:
#Factorial using recursive function.

import sys

#Function Definition
def fact(m):
    f = 1
    if m == 1:
        return 1
    else:
        f = m * fact(m-1)
        return f
    
#Variable Initialization
x = int(raw_input("Enter a Number : "))

#Function call
f = fact (x)

#Result
sys.stdout.write("\nFactorial of %d is %d"%(x,f))

Enter a Number : 5

Factorial of 5 is 120

Example 10.50, Page number: 369

In [54]:
#Display address of user defined function

import sys

#Function definition
def show():
    sys.stdout.write("\nAddress of function show() is : ")
    
#Function call
show()

#Result
sys.stdout.write("%u"%(id(show)))

Address of function show() is : 95041520

Example 10.51, Page number: 369

In [55]:
#Call function using pointer

import sys

#Function definition
def show():
    sys.stdout.write("\nAddress of function show() is : ")
    
#There is no pointer concept in python
p = id(show)
show()
sys.stdout.write("%u"%(id(show)))

Address of function show() is : 95041200

Example 10.52, Page number: 370

In [57]:
#Display the address of library function.

import sys
import os

#Result
sys.stdout.write("\nAddress of printf() is %u"%(id(sys.stdout.write)))
sys.stdout.write("\nAddress of scanf() is %u"%(id(sys.stdout.read)))
sys.stdout.write("\nAddress of clrscr() is %u"%(id(os.system('cls'))))

Address of printf() is 60743848
Address of scanf() is 60743848
Address of clrscr() is 4774132

Example 10.53, Page number: 371

In [59]:
#Call main() using pointer to main() function

import sys

#Variable Initilization
x = 0

#Function definition
def main(x):
    p = id(main)
    x += 1
    sys.stdout.write("\nCall %d Address of main() %u"%(x,id(main)))
    if x == 3:
        return
    main(x)
    
#function call
main(x)

Call 1 Address of main() 95040880
Call 2 Address of main() 95040880
Call 3 Address of main() 95040880
In [ ]: