DATA HANDLING (CLASS - XI)

 

DATA HANDLING

Chapter – 5

Class – 11

Introduction

Most of the computer programming language support data type, variables, operator and expression like fundamentals. Python also support these.

Data Types: Data Type specifies which type of value a variable can store. type() function is used to determine a variable's type in Python.

Data Types In Python

1. Number

2. String

3. Boolean

4. List

5. Tuple

6. Set

7. Dictionary

1. Number In Python: It is used to store numeric values.

Python has three numeric types:

1. Integers

2. Floating point numbers

3. Complex numbers.

1. Integers: Integers or int are positive or negative numbers with no decimal point. Integers in Python  are of unlimited size.

Example:

a= 100

b= -100

c= 10*20

print(a)

print(b)

print(c)

Output :-

100

-100

200

 

Type Conversion of Integer: int() function converts any data type to integer.

Example

a = "101"              # string

b=int(a)                # converts string data type to integer

c=int(122.4)        # converts float data type to integer.

print(b)

print(c)

Output :-

101

122

2. Floating point numbers: It is a positive or negative real numbers with a decimal point.

Example

a = 101.2

b = -101.4

c = 111.23

d = 2.3*3

print(a)

print(b)

print(c)

print(d)

Output :-

101.2

-101.4

111.23

6.8999999999999995

Type Conversion of Floating point numbers: float() function converts any data type to floating point number.

Example

a='301.4'              #string

b=float(a)             #converts string data type to floating point number.

c=float(121)        #converts integer data type to floating point number.

print(b)

print(c)

Output :-

301.4

121.0

3. Complex numbers: Complex numbers are combination of a real and imaginary part. Complex numbers are in the form of X+Yj, where X is a real part and Y is imaginary part.

Example

a = complex(5)                 # convert 5 to a real part val and zero imaginary part

print(a)

b=complex(101,23)         #convert 101 with real part and 23 as imaginary part

print(b)

Output :-

(5+0j)

(101+23j)

2. String In Python

A string is a sequence of characters. In python we can create string using single (' ') or double quotes (" "). Both are same in python.

Example

str='computer science'

print('str-', str) # print string

print('str[0]-', str[0]) # print first char 'h'

print('str[1:3]-', str[1:3]) # print string from postion 1 to 3 'ell'

print('str[3:]-', str[3:]) # print string staring from 3rd char 'llo world'

print('str *2-', str *2 ) # print string two times

print("str +'yes'-", str +'yes') # concatenated string

Output

str- computer science

str[0]- c

str[1:3]- om

str[3:]- puter science

str *2- computer sciencecomputer science

str +'yes'- computer scienceyes

(Loop) Iterating through string

e.g.

str='comp sc'

for i in str:

      print(i)

Output

c

o

m

p

s

c

3. Boolean In Python

 It is used to store two possible values either true or false.

e.g.

str="comp sc"

boo=str.isupper() # test if string contains upper case

print(boo)

Output

False

4.List In Python

List are collections of items and each item has its own index value.

5. Tuple In Python

List and tuple, both are same except ,a list is mutable python objects and tuple is immutable Python objects. Immutable Python objects mean you cannot modify the contents of a tuple once it is assigned.

6. Set In Python

It is an unordered collection of unique and immutable (which cannot be modified)items

e.g.

set1={11,22,33,22}

print(set1)

Output:

{33, 11, 22}

7. Dictionary In Python

It is an unordered collection of items and each item consist of a key and a value.

e.g.

dict = {'Subject': 'comp sc', 'class': '11'}

print(dict)

print ("Subject : ", dict['Subject'])

print ("class : ", dict.get('class'))

Output :

{'Subject': 'comp sc', 'class': '11'}

Subject : comp sc

class : 11

Operator

Operators are special symbols in Python that carry out arithmetic or logical computation. The value that the operator operates on is called the operand.

Arithmetic operators

Used for mathematical operation

# EMI Calculator program in Python

def emi_calculator(p, r, t):

    r = r / (12 * 100) # one month interest

    t = t * 12 # one month period

    emi = (p * r * pow(1 + r, t)) / (pow(1 + r, t) - 1)

    return emi

# driver code

principal = 10000;

rate = 10;

time = 2;

emi = emi_calculator(principal, rate, time);

print("Monthly EMI is= ", emi)

Comparison operators: used to compare values

Logical operators

Example

Bitwise operators: Used to manipulate bit values.

Example:

Python Membership Operators:  Test for membership in a sequence

Example

Python Identity Operators

Example:

Operators Precedence :highest precedence to lowest precedence table

Expression

Type conversion

math module

It is a standard module in Python. To use mathematical functions of this module,we have to import the module using import math.

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