CHAPTER 1

Question 1

Define Script.

Answer 1

a python program

Question 2

Define python command.

Answer 2

a python program statement

Question 3

Define shell.

Answer 3

commands and definitions are executed by the python interpreter.

Question 4

Python features.

Answer 4

a. simple and easy program structure.
b. portable and free available library.
c. easy for debugging and testing.
d. supports structured and functional programming methods as well as object-oriented programming.
e. provides dynamic type checking and very high-level dynamic data type.
f. it has automatic garbage collection.
g. integration with c++, c, CORBA, java is very easy.

Question 5

Types of objects.

Answer 5

scalar and non-scalar

Question 6

Scalar Objects

Answer 6

they are considered invisible objects.

example: int, float, bool, none.

Question 7

1. int
2. float
3. bool
4. none

Answer 7

1. used to represent integers(ex:- 3,4, -60, 02).
2. used to represent real numbers with decimal points(-0.5, 6.0, 9.9).
3. represent two boolean values that are true or false.
4. it is a type with a single value.

Question 8

Non-scalar objects

Answer 8

Strings

Question 9

Define expression.

Answer 9

combination of operators and objects.

Question 10

’==’ operator

’!=’ operator

’»>’

Answer 10

to check whether the two expressions are the same or the same two values.

to test whether the two expressions evaluate different values.

it indicates the user to type some code in the shell

Question 11

a//b

Answer 11

it means it will always return a result of type int since it returns the quotient and ignores the remainder. ex: 7/3 will return 3.

Question 12

a**b

Answer 12

a raised to the power b. ex: 5**3=125

Question 13

precedence

Answer 13

Parentheses&raquo_space; Exponent&raquo_space; Unary plus, Unary minus, Bitwise NOT&raquo_space; Multiplication, Division, Floor division, Modulus&raquo_space; Addition, Subtraction&raquo_space; Bitwise shift operators&raquo_space; Bitwise AND&raquo_space; Bitwise XOR&raquo_space; Bitwise OR&raquo_space; Comparisons, Identity, Membership operators&raquo_space; Logical NOT&raquo_space; Logical AND&raquo_space; Logical OR

Question 14

Define variables.

Answer 14

a way to associate names with objects. it is just a name.

Question 15

What is an assignment statement?

Answer 15

it is used to assign value to the variable. It associates the name of the variable with the object represented by the expression to the right side of the assignment operator(=).

Question 16

strings

Answer 16

represented by str.
can be written between single or double-quotes.
an ordered sequence of characters: “hello” ‘Sammy’ “2000”.

Question 17

overloading operator

2. *

Answer 17

1. it means addition when applied to two numbers and concatenation when applied to two strings.
2. it means multiplication when applied to two numbers and when applied to an int and string it will duplicate the str.
   ex: 4 * ‘p’ = ‘p’+’p’+’p’+’p’

Question 18

Define slicing.

Answer 18

it is used to extract substrings of arbitrary length.

Question 19

indexing

Answer 19

in python, it starts from 0 and ends at length-1.
s[start: end] means index start and ends at index end-1.
ex: ‘pqr’[1:3]= ‘qr’
if the value before the colon is omitted then it considers 0 as default and if the value is omitted after colon then it considers the length of the string.
‘pqr’[:] == ‘pqr’[0:len(‘pqr’)]

Question 20

Branching programs

Answer 20

it has three parts:

1. a test condition.
2. a block of code that is executed if the test evaluates to true
3. an optional block o code that is executed if the test evaluates to false.

Question 21

Syntax of the conditional statement

Answer 21

if Boolean expression:
block of code
else:
block of code

Question 22

Iteration

Answer 22

another form of control structure.

Question 23

built-in data types in python.

Answer 23

numbers, list, tuple, string, set, dictionary