Python Strings

Creating a string

In Python, you can create a string by enclosing characters in single or double quotes. For example:

string1 = 'This is a string'
string2 = "This is also a string"

You can also use triple quotes to create a multi-line string:

string3 = '''This is a
multi-line string'''

string4 = """This is also a
multi-line string"""

String Characteristics

Strings in Python are immutable, which means that you cannot change the characters in a string once it has been created. However, you can create a new string by concatenating (joining) two or more strings together. For example:

string1 = 'Hello'
string2 = 'World'

# Concatenate the strings
string3 = string1 + ' ' + string2
print(string3)  # Output: "Hello World"

You can also use the * operator to repeat a string a certain number of times:

string4 = 'Hello' * 3
print(string4)  # Output: "HelloHelloHello"

Looping in strings

You can loop through the characters in a string using a for loop. For example:

string = 'Hello World'

for char in string:
    print(char)

# Output:
# H
# e
# l
# l
# o
#
# W
# o
# r
# l
# d

You can also use the enumerate() function to loop through a string and get the index of each character:

string = 'Hello World'

for index, char in enumerate(string):
    print(f'Character at index {index}: {char}')

# Output:
# Character at index 0: H
# Character at index 1: e
# Character at index 2: l
# Character at index 3: l
# Character at index 4: o
# Character at index 5:
# Character at index 6: W
# Character at index 7: o
# Character at index 8: r
# Character at index 9: l
# Character at index 10: d

String length

You can use the len() function to get the length of a string, which is the number of characters it contains. For example:

string = 'Hello World'
string_length = len(string)
print(string_length)  # Output: 11

You can also use the len() function to get the length of a string when you are looping through it. For example:

string = 'Hello World'

for index, char in enumerate(string):
    print(f'Character at index {index}: {char}')
    if index == len(string) - 1:
        print('This is the last character')

# Output:
# Character at index 0: H
# Character at index 1: e
# Character at index 2: l
# Character at index 3: l
# Character at index 4: o