Question

Write about strings and input in python. Explain with 2 examples.

Answer 1

String in Python:

A string is a sequence of characters.In Python, a string is a sequence of Unicode characters.

creating a string in Python:
Strings can be created by enclosing characters inside a single quote or double-quotes.

Example:
# defining strings in Python

my_string = 'Hello'
print(my_string)
>> Hello

my_string = "Hello"
print(my_string)
>> Hello

Access characters in a string:
We can access individual characters using indexing and a range of characters using slicing.
The index of -1 refers to the last item, -2 to the second last item and so on. We can access a range of items in a string by using the slicing operator (:).

Example:

#Accessing string characters in Python
str = 'AGGREGATE ' ''
print('str = ', str)

#first character
print('str[0] = ', str[0])
>> A

#last character
print('str[-1] = ', str[-1])
>> E

#slicing 2nd to 5th character
print('str[1:5] = ', str[1:5])
>> GGRE

#slicing 6th to 2nd last character
print('str[5:-2] = ', str[5:-2])
>> GA

String Operations:
Concatenation of Two or More Strings :
Joining of two or more strings into a single one is called Concatenation.

The + operator does this in Python. Simply writing two string literals together also concatenates them.
The * operator can be used to repeat the string for a given number of times.

Example:

# Python String Operations
str1 = 'Hello'
str2 ='World!'

# using +
print('str1 + str2 = ', str1 + str2)
>> HelloWorld!

# using *
print('str1 * 3 =', str1 * 3)
>> HelloHelloHello

Iterating Through a string:
Iterate through a string using a for loop:

Example:

# Iterating through a string
count = 0
for letter in 'Hello World':
if(letter == 'l'):
count += 1
print(count,'letters found')
>> 3 Letters found

Python Input:

In Python, we have the input() function to allow this. The syntax for input() is:

input([prompt])

where prompt is the string we wish to display on the screen. It is optional.

Example:

name = input('What is your name? ')
What is your name? chandu
>>> name
'chandu'

>>> num = input('Enter a number: ')
Enter a number: 10
>>> num
'10'

Here, we can see that the entered value 10 is a string, not a number. To convert this into a number we can use int() or float() functions.

>>> int('10')
10
>>> float('10')
10.0