Python Fundamentals

Question 1

A keyword is a reserved word carrying special meaning and purpose.

Question 2

Identifiers are the user defined names for different parts of a program.

Question 3

Literals are the fixed values.

Question 4

Operators are the symbols that trigger some computation or action.

Question 5

An expression is a legal combination of symbols that represents a value.

Question 6

Non-executable, additional lines added to a program, are known as comments.

Question 7

In Python, the comments begin with # character.

Question 8

Python is a case sensitive language.

Question 9

The print( ) function prints the value of a variable/expression.

Question 10

The input( ) function gets the input from the user.

Question 11

The input( ) function returns the read value as of string type.

Question 12

To convert an input( )'s value in integer type, int( ) function is used.

Question 13

To convert an input( )'s value in floating-point type, float( ) function is used.

Question 14

Strings can be created with single quotes, double quotes and triple quotes.

Question 1

Special meaning words of Pythons, fixed for specific functionality are called .......... .

1. Identifiers
2. functions
3. Keywords ✓
4. literals

Question 2

Names given to different parts of a Python program are .......... .

1. Identifiers ✓
2. functions
3. Keywords
4. literals

Question 3

Data items having fixed value are called .......... .

1. Identifiers
2. functions
3. Keywords
4. literals ✓

Question 4

Which of the following is/are correct ways of creating strings ?

1. name = Jiya
2. name = 'Jiya' ✓
3. name = "Jiya" ✓
4. name = (Jiya)

Question 5

Which of the following are keyword(s) ?

1. name
2. Print
3. print ✓
4. input ✓

Question 6

Which of the following are valid identifiers ?

1. my name
2. _myname ✓
3. myname ✓
4. my-name

Question 7

Which of the following are literals ?

1. myname
2. "Radha" ✓
3. 24.5 ✓
4. 24A

Question 8

Escape sequences are treated as .......... .

1. strings
2. characters ✓
3. integers
4. none of these

Question 9

Which of the following is an escape sequence for a tab character ?

1. \a
2. \t ✓
3. \n
4. \b

Question 10

Which of the following is an escape sequence for a newline character ?

1. \a
2. \t
3. \n ✓
4. \b

Question 11

Which of the following is not a legal integer type value in Python ?

1. Decimal
2. Octal
3. Hexadecimal
4. Roman ✓

Question 12

Which of the following symbols are not legal in an octal value ?

1. 7
2. 8 ✓
3. 9 ✓
4. 0

Question 13

Value 17.25 is equivalent to

1. 0.1725E-2
2. 0.1725E+2 ✓
3. 1725E2
4. 0.1725E2 ✓

Question 14

Value 0.000615 is equivalent to

1. 615E3
2. 615E-3
3. 0.615E3
4. 0.615E-3 ✓

Question 15

Which of the following is/are expression(s) ?

1. a+b-5 ✓
2. a
3. -5
4. b-5 ✓

Question 16

The lines beginning with a certain character, and which are ignored by a compiler and not executed, are called ..........

1. operators
2. operands
3. functions
4. comments ✓

Question 17

Which of the following can be used to create comments ?

1. //
2. # ✓
3. '''
4. ''' . . . ''' ✓

Question 18

Which of the following functions print the output to the console ?

1. Output( )
2. Print( )
3. Echo( )
4. print( ) ✓

Question 19

Select the reserved keyword in Python.

1. else
2. import
3. print
4. all of these ✓

Question 20

The input( ) returns the value as .......... type.

1. integer
2. string ✓
3. floating point
4. none of these

Question 21

To convert the read value through input( ) into integer type, ..........( ) is used.

1. floating
2. float
3. int ✓
4. integer

Question 22

To convert the read value through input( ) into a floating point number, ..........( ) is used.

1. floating
2. float ✓
3. int
4. integer

Question 23

To print a line a text without ending it with a newline, .......... argument is used with print( )

1. sep
2. newline
3. end ✓
4. next

Question 24

The default separator character of print( ) is ..........

1. tab
2. space ✓
3. newline
4. dot

Question 25

To give a different separator with print( ) .......... argument is used.

1. sep ✓
2. separator
3. end
4. tab

Question 1

Keywords can be used as identifier names.
False

Question 2

The identifiers in Python can begin with an underscore.
True

Question 3

0128 is a legal literal value in Python.
False

Question 4

0x12EFG is a legal literal value in Python.
False

Question 5

0123 is a legal literal value in Python.
True

Question 6

Variables once assigned a value can be given any other value.
True

Question 7

Variables are created when they are first assigned their value.
True

Question 8

Python variables support dynamic typing.
True

Question 9

You can rename a keyword.
False

Question 10

String values in Python can be single line strings, and multi-line strings.
True

Question 11

A variable can contain values of different types at different times.
True

Question 12

Expressions contain values/variables along with operators.
True

Question 1

What are tokens in Python ? How many types of tokens are allowed in Python ? Examplify your answer.

Question 2

How are keywords different from identifiers ?

Question 3

What are literals in Python ? How many types of literals are allowed in Python ?

Question 4

Can nongraphic characters be used in Python ? How ? Give examples to support your answer.

Question 5

How are floating constants represented in Python ? Give examples to support your answer.

Question 6

How are string-literals represented and implemented in Python ?

Question 7

Which of these is not a legal numeric type in Python ? (a) int (b) float (c) decimal.

Question 8

Which argument of print( ) would you set for:

(i) changing the default separator (space) ?
(ii) printing the following line in current line ?

Question 9

What are operators ? What is their function ? Give examples of some unary and binary operators.

Question 10

What is an expression and a statement ?

Question 11

What all components can a Python program contain ?

Question 12

What do you understand by block/code block/suite in Python ?

Question 13

What is the role of indentation in Python ?

Question 14

What are variables ? How are they important for a program ?

Question 15

What do you understand by undefined variable in Python ?

Question 16

What is Dynamic Typing feature of Python ?

Question 17

What would the following code do : X = Y = 7 ?

Question 18

What is the error in following code : X, Y = 7 ?

Question 19

Following variable definition is creating problem X = 0281, find reasons.

Question 20

"Comments are useful and easy way to enhance readability and understandability of a program." Elaborate with examples.

Question 1

From the following, find out which assignment statement will produce an error. State reason(s) too.

(a) x = 55
(b) y = 037
(c) z = 0o98
(d) 56thnumber = 3300
(e) length = 450.17
(f) !Taylor = 'Instant'
(g) this variable = 87.E02
(h) float = .17E - 03
(i) FLOAT = 0.17E - 03

Question 2

How will Python evaluate the following expression ?

(i) 20 + 30 * 40

Question 3

Find out the error(s) in following code fragments:

(i)

temperature = 90
print temperature

Question 4

What will be the output produced by following code fragment (s) ?

(i)

X = 10          
X = X + 10         
X = X - 5       
print (X)       
X, Y = X - 2, 22
print (X, Y)    

Output

15
13 22

Explanation

1. X = 10 ⇒ assigns an initial value of 10 to X.
2. X = X + 10 ⇒ X = 10 + 10 = 20. So value of X is now 20.
3. X = X - 5 ⇒ X = 20 - 5 = 15. X is now 15.
4. print (X) ⇒ print the value of X which is 15.
5. X, Y = X - 2, 22 ⇒ X, Y = 13, 22.
6. print (X, Y) ⇒ prints the value of X which is 13 and Y which is 22.

(ii)

first = 2
second = 3
third = first * second
print (first, second, third) 
first = first + second + third
third = second * first
print (first, second, third)

Output

2 3 6
11 3 33

Explanation

1. first = 2 ⇒ assigns an initial value of 2 to first.
2. second = 3 ⇒ assigns an initial value of 3 to second.
3. third = first * second ⇒ third = 2 * 3 = 6. So variable third is initialized with a value of 6.
4. print (first, second, third) ⇒ prints the value of first, second, third as 2, 3 and 6 respectively.
5. first = first + second + third ⇒ first = 2 + 3 + 6 = 11
6. third = second * first ⇒ third = 3 * 11 = 33
7. print (first, second, third) ⇒ prints the value of first, second, third as 11, 3 and 33 respectively.

(iii)

side = int(input('side') )  #side given as 7
area = side * side
print (side, area)

Output

side7
7 49

Explanation

1. side = int(input('side') ) ⇒ This statements asks the user to enter the side. We enter 7 as the value of side.
2. area = side * side ⇒ area = 7 * 7 = 49.
3. print (side, area) ⇒ prints the value of side and area as 7 and 49 respectively.

Question 5

What is the problem with the following code fragments ?

(i)

a = 3
    print(a)
b = 4
    print(b)
s = a + b
    print(s)

Question 6

Predict the output:

(a)

x = 40
y = x + 1       
x = 20, y + x    
print (x, y)

Output

(20, 81) 41

Explanation

1. x = 40 ⇒ assigns an initial value of 40 to x.
2. y = x + 1 ⇒ y = 40 + 1 = 41. So y becomes 41.
3. x = 20, y + x ⇒ x = 20, 41 + 40 ⇒ x = 20, 81. This makes x a Tuple of 2 elements (20, 81).
4. print (x, y) ⇒ prints the tuple x and the integer variable y as (20, 81) and 41 respectively.

(b)

x, y = 20, 60
y, x, y = x, y - 10, x + 10
print (x, y)

Output

50 30

Explanation

1. x, y = 20, 60 ⇒ assigns an initial value of 20 to x and 60 to y.
2. y, x, y = x, y - 10, x + 10
   ⇒ y, x, y = 20, 60 - 10, 20 + 10
   ⇒ y, x, y = 20, 50, 30
   First RHS value 20 is assigned to first LHS variable y. After that second RHS value 50 is assigned to second LHS variable x. Finally third RHS value 30 is assigned to third LHS variable which is again y. After this assignment, x becomes 50 and y becomes 30.
3. print (x, y) ⇒ prints the value of x and y as 50 and 30 respectively.

(c)

a, b = 12, 13  
c, b = a*2, a/2
print (a, b, c)

Output

12 6.0 24

Explanation

1. a, b = 12, 13 ⇒ assigns an initial value of 12 to a and 13 to b.
2. c, b = a*2, a/2 ⇒ c, b = 12*2, 12/2 ⇒ c, b = 24, 6.0. So c has a value of 24 and b has a value of 6.0.
3. print (a, b, c) ⇒ prints the value of a, b, c as 12, 6.0 and 24 respectively.

(d)

a, b = 12, 13
print (print(a + b))

Output

25
None

Explanation

1. a, b = 12, 13 ⇒ assigns an initial value of 12 to a and 13 to b.
2. print (print(a + b)) ⇒ First print(a + b) function is called which prints 25. After that, the outer print statement prints the value returned by print(a + b) function call. As print function does not return any value so outer print function prints None.

Question 7

Predict the output

a, b, c = 10, 20, 30
p, q, r = c - 5, a + 3, b - 4
print ('a, b, c :', a, b, c, end = '')
print ('p, q, r :', p, q, r)

Output

a, b, c : 10 20 30p, q, r : 25 13 16

Explanation

1. a, b, c = 10, 20, 30 ⇒ assigns initial value of 10 to a, 20 to b and 30 to c.
2. p, q, r = c - 5, a + 3, b - 4
   ⇒ p, q, r = 30 - 5, 10 + 3, 20 - 4
   ⇒ p, q, r = 25, 13, 16.
   So p is 25, q is 13 and r is 16.
3. print ('a, b, c :', a, b, c, end = '') ⇒ This statement prints a, b, c : 10 20 30. As we have given end = '' so output of next print statement will start in the same line.
4. print ('p, q, r :', p, q, r) ⇒ This statement prints p, q, r : 25 13 16

Question 8

Find the errors in following code fragment

(a)

y = x + 5
print (x, Y)

Question 9

Find the errors in following code fragment : (The input entered is XI)

c = int (input ( "Enter your class") )
print ("Your class is", c)

Question 10

Consider the following code :

name = input ("What is your name?")
print ('Hi', name, ',')
print ("How are you doing?")

was intended to print output as

Hi <name>, How are you doing ?

But it is printing the output as :

Hi <name>,
How are you doing?

What could be the problem ? Can you suggest the solution for the same ?

Question 11

Find the errors in following code fragment :

c = input( "Enter your class" )
print ("Last year you were in class") c - 1

Question 12

What will be returned by Python as result of following statements?

(a) >>> type(0)

Question 13

What will be the output produced by following code ?

(a) >>> str(print())+"One"

Output

NoneOne

Explanation

print() function doesn't return any value so its return value is None. Hence, str(print()) becomes str(None). str(None) converts None into string 'None' and addition operator joins 'None' and 'One' to give the final output as 'NoneOne'.

(b) >>> str(print("hello"))+"One"

Output

hello
NoneOne

Explanation

First, print("hello") function is executed which prints the first line of the output as hello. The return value of print() function is None i.e. nothing. str() function converts it into string and addition operator joins 'None' and 'One' to give the second line of the output as 'NoneOne'.

(c) >>> print(print("Hola"))

Output

Hola
None

Explanation

First, print("Hola") function is executed which prints the first line of the output as Hola. The return value of print() function is None i.e. nothing. This is passed as argument to the outer print function which converts it into string and prints the second line of output as None.

(d) >>> print (print ("Hola", end = " "))

Output

Hola None

Explanation

First, print ("Hola", end = " ") function is executed which prints Hola. As end argument is specified as " " so newline is not printed after Hola. The next output starts from the same line. The return value of print() function is None i.e. nothing. This is passed as argument to the outer print function which converts it into string and prints None in the same line after Hola.

Question 14

Carefully look at the following code and its execution on Python shell. Why is the last assignment giving error ?

>>> a = 0o12
>>> print(a)
10
>>> b = 0o13
>>> c = 0o78
    File "<python-input-41-27fbe2fd265f>", line 1
    c = 0o78
         ^
SyntaxError : invalid syntax         

Question 15

Predict the output

a, b, c = 2, 3, 4
a, b, c = a*a, a*b, a*c
print(a, b, c)

Output

4 6 8

Explanation

1. a, b, c = 2, 3, 4 ⇒ assigns initial value of 2 to a, 3 to b and 4 to c.
2. a, b, c = a*a, a*b, a*c
   ⇒ a, b, c = 2*2, 2*3, 2*4
   ⇒ a, b, c = 4, 6, 8
3. print(a, b, c) ⇒ prints values of a, b, c as 4, 6 and 8 respectively.

Question 16

The id( ) can be used to get the memory address of a variable. Consider the adjacent code and tell if the id( ) functions will return the same value or not(as the value to be printed via print() ) ? Why ?
[There are four print() function statements that are printing id of variable num in the code shown on the right.

num = 13
print( id(num) )
num = num + 3
print( id(num) )
num = num - 3
print( id(num) )
num = "Hello"
print( id(num) )

Question 17

Consider below given two sets of codes, which are nearly identical, along with their execution in Python shell. Notice that first code-fragment after taking input gives error, while second code-fragment does not produce error. Can you tell why ?

(a)

>>> print(num = float(input("value1:")) )  
value1:67

TypeError: 'num' is an invalid keyword argument for this function

(b)

>>> print(float(input("valuel:")) )
value1:67

67.0

Question 18

Predict the output of the following code :

days = int (input ("Input days : ")) * 3600 * 24
hours = int(input("Input hours: ")) * 3600 
minutes = int(input("Input minutes: ")) * 60 
seconds = int(input("Input seconds: ")) 
time = days + hours + minutes + seconds 
print("Total number of seconds", time)

If the input given is in this order : 1, 2, 3, 4

Output

Input days : 1
Input hours: 2
Input minutes: 3
Input seconds: 4
Total number of seconds 93784

Question 19

What will the following code result into ?

n1, n2 = 5, 7
n3 = n1 + n2
n4 = n4 + 2
print(n1, n2, n3, n4)

Question 20

Correct the following program so that it displays 33 when 30 is input.

val = input("Enter a value")
nval = val + 30
print(nval)

Question 1

Write a program that displays a joke. But display the punchline only when the user presses enter key.
(Hint. You may use input( ))

Solution

print("Why is 6 afraid of 7?")
input("Press Enter")
print("Because 7 8(ate) 9 :-)")

Output

Why is 6 afraid of 7?
Press Enter
Because 7 8(ate) 9 :-)

Question 2

Write a program to read today's date (only del part) from user. Then display how many days are left in the current month.

Solution

day = int(input("Enter day part of today's date: "))
totalDays = int(input("Enter total number of days in this month: "))
daysLeft = totalDays - day
print(daysLeft, "days are left in current month")

Output

Enter day part of today's date: 16
Enter total number of days in this month: 31
15 days are left in current month

Question 3

Write a program that generates the following output :
5
10
9
Assign value 5 to a variable using assignment operator (=) Multiply it with 2 to generate 10 and subtract 1 to generate 9.

Solution

a = 5
print(a)
a = a * 2
print(a)
a = a - 1
print(a)

Output

5
10
9

Question 4

Modify above program so as to print output as 5@10@9.

Solution

a = 5
print(a, end='@')
a = a * 2
print(a, end='@')
a = a - 1
print(a)

Output

5@10@9

Question 5

Write the program with maximum three lines of code and that assigns first 5 multiples of a number to 5 variables and then print them.

Solution

a = int(input("Enter a number: "))
b, c, d, e = a * 2, a * 3, a * 4, a * 5
print(a, b, c, d, e)

Output

Enter a number: 2
2 4 6 8 10

Question 6

Write a Python program that accepts radius of a circle and prints its area.

Solution

r = float(input("Enter radius of circle: "))
a = 3.14159 * r * r
print("Area of circle =", a)

Output

Enter radius of circle: 7.5
Area of circle = 176.7144375

Question 7

Write Python program that accepts marks in 5 subjects and outputs average marks.

Solution

m1 = int(input("Enter first subject marks: "))
m2 = int(input("Enter second subject marks: "))
m3 = int(input("Enter third subject marks: "))
m4 = int(input("Enter fourth subject marks: "))
m5 = int(input("Enter fifth subject marks: "))
avg = (m1 + m2+ m3+ m4 + m5) / 5;
print("Average Marks =", avg)

Output

Enter first subject marks: 65
Enter second subject marks: 78
Enter third subject marks: 79
Enter fourth subject marks: 80
Enter fifth subject marks: 85
Average Marks = 77.4

Question 8

Write a short program that asks for your height in centimetres and then converts your height to feet and inches. (1 foot = 12 inches, 1 inch = 2.54 cm).

Solution

ht = int(input("Enter your height in centimeters: "))
htInInch = ht / 2.54;
feet = htInInch // 12;
inch = htInInch % 12;
print("Your height is", feet, "feet and", inch, "inches")

Output

Enter your height in centimeters: 162
Your height is 5.0 feet and 3.7795275590551185 inches

Question 9

Write a program to read a number n and print n², n³ and n⁴.

Solution

n = int(input("Enter n: "))
n2, n3, n4 = n ** 2, n ** 3, n ** 4
print("n =", n)
print("n^2 =", n2)
print("n^3 =", n3)
print("n^4 =", n4)

Output

Enter n: 2
n = 2
n^2 = 4
n^3 = 8
n^4 = 16

Question 10

Write a program to find area of a triangle.

Solution

h = float(input("Enter height of the triangle: "))
b = float(input("Enter base of the triangle: "))
area = 0.5 * b * h
print("Area of triangle = ", area)

Output

Enter height of the triangle: 2.5
Enter base of the triangle: 5
Area of triangle =  6.25

Question 11

Write a program to compute simple interest and compound interest.

Solution

p = float(input("Enter principal: "))
r = float(input("Enter rate: "))
t = int(input("Enter time: "))
si = (p * r * t) / 100
ci = p * ((1 + (r / 100 ))** t) - p
print("Simple interest = ", si)
print("Compound interest = ", ci)

Output

Enter principal: 15217.75
Enter rate: 9.2
Enter time: 3
Simple interest =  4200.098999999999
Compound interest =  4598.357987312007

Question 12

Write a program to input a number and print its first five multiples.

Solution

n = int(input("Enter number: "))
print("First five multiples of", n, "are")
print(n, n * 2, n * 3, n * 4, n * 5)

Output

Enter number: 5
First five multiples of 5 are
5 10 15 20 25

Question 13

Write a program to read details like name, class, age of a student and then print the details firstly in same line and then in separate lines. Make sure to have two blank lines in these two different types of prints.

Solution

n = input("Enter name of student: ")
c = int(input("Enter class of student: "))
a = int(input("Enter age of student: "))
print("Name:", n, "Class:", c, "Age:", a)
print()
print()
print("Name:", n)
print("Class:", c)
print("Age:", a)

Output

Enter name of student: Kavya
Enter class of student: 11
Enter age of student: 17
Name: Kavya Class: 11 Age: 17


Name: Kavya
Class: 11
Age: 17

Question 14

Write a program to input a single digit(n) and print a 3 digit number created as <n(n + 1)(n + 2)> e.g., if you input 7, then it should print 789. Assume that the input digit is in range 1-7.

Solution

d = int(input("Enter a digit in range 1-7: "))
n = d * 10 + d + 1
n = n * 10 + d + 2
print("3 digit number =", n)

Output

Enter a digit in range 1-7: 7
3 digit number = 789

Question 15

Write a program to read three numbers in three variables and swap first two variables with the sums of first and second, second and third numbers respectively.

Solution

a = int(input("Enter first number: "))
b = int(input("Enter second number: "))
c = int(input("Enter third number: "))
print("The three number are", a, b, c)
a, b = a + b, b + c
print("Numbers after swapping are", a, b, c)

Output

Enter first number: 10
Enter second number: 15
Enter third number: 20
The three number are 10 15 20
Numbers after swapping are 25 35 20