In this lesson we want to learn about Python String Methods.
What is Python String ?
In Python string is a sequence of characters enclosed within single, double or triple quotes. Strings can contain alphanumeric characters, symbols and punctuation marks. They are used to represent text or a combination of characters. In Python, strings are immutable objects, meaning their value cannot be changed once they have been created. The built-in str class in Python provides many methods to manipulate and format strings.
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Python String Methods
Python has several built in methods for working with strings. these are some of the most commonly used string methods:
str.capitalize(): Returns a copy of the string with the first character capitalized.str.center(width, fillchar): Returns a string of specified width, padded with the specifiedfillchar(or spaces by default) so that the original string is centered.str.count(sub, start, end): Returns the number of non-overlapping occurrences ofsubin the string, between the indicesstartandend.str.endswith(suffix, start, end): ReturnsTrueif the string ends with the specifiedsuffix, between the indicesstartandend.str.find(sub, start, end): Returns the lowest index in the string wheresubis found, between the indicesstartandend. Returns -1 ifsubis not found.str.format(*args, **kwargs): Returns a string with placeholders replaced by the specified arguments.str.isalnum(): ReturnsTrueif all characters in the string are alphanumeric (letters or digits).str.isalpha(): ReturnsTrueif all characters in the string are alphabetical.str.isdigit(): ReturnsTrueif all characters in the string are digits.str.islower(): ReturnsTrueif all characters in the string are lowercase.str.join(iterable): Concatenates all elements in theiterableinto a single string, separated by the original string.str.replace(old, new, count): Returns a copy of the string with all occurrences ofoldreplaced withnew. The optionalcountargument specifies the maximum number of replacements to make.
This is an example of using some of the string methods:
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# Define a string message = "Hello, World!" # Use the capitalize() method to capitalize the first character capitalized_message = message.capitalize() print(capitalized_message) # Use the count() method to count the number of 'l' characters count = message.count('l') print(count) # Use the endswith() method to check if the string ends with '!' ends_with_exclamation = message.endswith('!') print(ends_with_exclamation) # Use the format() method to replace placeholders with values formatted_message = "{} is a great place to learn {}!".format("OpenAI", "AI") print(formatted_message) # Use the join() method to concatenate a list of strings into a single string words = ["Welcome", "to", "the", "world", "of", "AI"] joined_words = " ".join(words) print(joined_words) |
In this example, we define a string message and use several string methods to perform operations on the string. We use the capitalize() method to capitalize the first character of the string, the count() method to count the number of 'l' characters in the string, the endswith()
Run the complete code and this will be the result
