String Data Type

A string is a sequence of characters.

String Data Type

str1="hello"
print(type(str1))
Ans: <class ‘str’>

str2='123'
print(type(str2))
Ans: <class ‘str’>

str2='123'
ch=int(str2)
print(type(ch))
Ans: <class ‘int’>

Adding and Concatenation using ‘+’

Adding to the two string using the ‘+’

str1="hello"
str2='paris'
add1=str1+str2
print(add1)
Ans: Hello Paris

Adding to the two string using the ‘+’ but even the numeric values here is also a string adding any numeric value to it will cause error.

str2='123'
ch=str2+1
print(ch)
Ans: Error String type cannot add any numeric 1.

Before adding any value first it needs to change its type ‘int’, then any addition can take place.

str2='123'
ch=int(str2)+1
print(ch)
Ans: 124

s=’1’+’1′
print(s)
Ans: ’11’
 
s=’1’+’1′
print(int(s)+1)
Ans: True

Comparison

'Hello'=='Hello'
Ans: True
 
'Hello'=='hello'
Ans: False
 
'1'==1
Ans: False
 
'1'=='1'
Ans: True

Array

fruit='apple'
print(fruit[1])
Ans: ‘p’

fruit='banana'
x=2
print(fruit[x+2])
Ans: ‘n’

For Loop

fruit='apple'
for i in range(0,5):
    print(fruit[i])
Ans:
a
p
p
l
e

fruit='apple'
for i in range(0,6):
    print(fruit[i])
Ans:
a
p
p
l
e
Error: No index value

for i in range(0,len(fruit)):
    print(fruit[i])
Ans:
a
p
p
l
e 

fruit='apple'
for letter in fruit:
    print(letter)
Ans:
a
p
p
l
e 

To find the response of array in the one line then ‘sys’ library can be used

import sys
for i in range(0,len(fruit)):
    sys.stdout.write(fruit[i])
Ans: apple

While Loop with the len function

fruit='apple'
i=0
while i<len(fruit):
    ch=fruit[i]
    print(i,ch)
    i=i+1
Ans:
0 a
1 p
2 p
3 l
4 e

word='banana'
count=0
for letter in word:
    if letter=='a':
    count=count+1
    print(count)
Ans:
1
2
3

String Functions
Length of the string

fruit='apple'
len(fruit)
Ans: 5

Creating Arrays from the line

str1 = "I love my country"
str1[0:]
Ans: 'I love my country'
 
str1[0:10]
Ans: 'I love my'
 
str1[3:4]
Ans: 'o'