Python Strings

In Python, a string is a sequence of Unicode characters. Unicode was introduced to include every character in all languages and bring uniformity in encoding.

String Creation

Python provides multiple number of ways to create a string literal

#String Creation

#Enclosed with single quotes
single_quoted_data = 'I am created with single quote'
print(single_quoted_data)

#Enclosed with double quotes
double_quoted_data = "I am created with double quotes"
print(double_quoted_data)

#Enclosed with triple single quotes
triple_single_quoted_data = '''I am created
with
triple single quotes'''
print(triple_single_quoted_data)

#Enclosed with triple double quotes
triple_double_quoted_data = """I am created
with
triple double quotes"""
print(triple_double_quoted_data)

Output

I am created with single quote
I am created with double quotes
I am created
with
triple single quotes
I am created
with
triple double quotes

String Reading

Read a character with the help of positive and negative index value

P	Y	T	H	O	N
0	1	2	3	4	5
-6	-5	-4	-3	-2	-1

Every character have one positive and negative index in the string like the above example

#String Reading
school_name = "RATHNASCHOOLS"

#Reading the first character of the string
print(school_name[0])
print(school_name[-13])

#Reading the second character of the string
print(school_name[1])
print(school_name[-12])

#Reading the last character of the string
print(school_name[12])
print(school_name[-1])

Output

R
R
A
A
S
S

String Update

Strings are immutable, which means that cannot update once created

#String Update
school_name = "RATHNASCHOOLS"

#Item assignment impossible for immutable objects
school_name[1] = "E"

Output

Traceback (most recent call last):
File "<string>", line 5, in <module>
TypeError: 'str' object does not support item  assignment

Recreation of entire object is the only way for update the immutable objects in python

#String Update
school_name = "RATHNASCHOOLS"

#Object Recreation
school_name = "RETHNASCHOOLS"
print(school_name)

Output

RETHNASCHOOLS

String Deletion

Strings are immutable, which means that cannot delete once created

#String Deletion
school_name = "RATHNASCHOOLS"

#Item deletion impossible for immutable objects
del school_name[0]

Output

Traceback (most recent call last):
File "<string>", line 5, in <module>
TypeError: 'str' object doesn't support item deletion

Entire object can delete but not a substring in python

#String Deletion
school_name = "RATHNASCHOOLS"

#Entire object deletion is possible
del school_name
print(school_name)

String Slicing

String slice helps to return the required substring for the given string

string_name(start Index: stop Index: step Value(optional)]

• start Index Not declare means, first value index consider by python

• stop Index Not declare means, last value index consider by python

P	Y	T	H	O	N
0	1	2	3	4	5
-6	-5	-4	-3	-2	-1

#String Slicing
school_name = "RATHNASCHOOLS"

#Print the first three characters
print(school_name[0:3])
print(school_name[-13:3])
print(school_name[:3])

#Print the middle three characters
print(school_name[6:9])
print(school_name[-7:9])

#Print the last two characters
print(school_name[11:13])
print(school_name[-2:13])
print(school_name[11:])

Output

RAT
RAT
RAT
SCH
SCH
LS
LS
LS