100 Days Of Code - String Methods Lecture

Overview

• The lecture focuses on various methods for handling strings in Python.
• Strings are an essential data type, and the session covers operations that can be performed on strings.

Key String Methods

Immutability of Strings

• Strings in Python are immutable.
• You cannot change a string in place; instead, operations return a new string.
• Example: a = "Harry"; a.upper() returns a new string "HARRY" without changing a.

Upper and Lower Methods

• upper(): Converts all characters in a string to uppercase.
• lower(): Converts all characters in a string to lowercase.

Strip Methods

• rstrip(): Removes trailing characters from a string.
  • Example: a.rstrip("!") removes exclamation marks from the end.

Replace Method

• replace(old, new): Replaces all occurrences of a substring with another substring.
  • Example: a.replace("harry", "John") replaces "harry" with "John".

Split Method

• split(): Splits a string into a list based on a delimiter.
  • Example: Splitting a string on space creates a list of words.

Capitalize Method

• capitalize(): Capitalizes the first character of the string and lowers all others.

Center Method

• center(width): Centers the string in a field of given width by padding with spaces.

Count Method

• count(substring): Returns the number of occurrences of a substring in the string.

Endswith Method

• endswith(suffix): Checks if the string ends with the specified suffix.
  • Can specify start and end positions.

Find and Index Methods

• find(substring): Returns the index of the first occurrence of the substring. Returns -1 if not found.
• index(substring): Similar to find, but raises an exception if the substring is not found.

Alphanumeric Check Methods

• isalnum(): Returns True if all characters in the string are alphanumeric.
• isalpha(): Returns True if all characters in the string are alphabetic.

Case Check Methods

• islower(): Checks if all alphabetic characters in the string are lowercase.
• isupper(): Checks if all alphabetic characters in the string are uppercase.

Printable Check Method

• isprintable(): Checks if all characters in the string are printable.

Space Check Method

• isspace(): Returns True if there are only whitespace characters in the string.

Title Check Method

• istitle(): Returns True if the string is titlecased (first letter of each word is uppercase).

Swapcase and Title Methods

• swapcase(): Swaps case of all letters in the string.
• title(): Converts the string to title case.

Additional Information

• The lecture was presented with examples using Python code in a Repl environment.
• There was a brief discussion on the setup used for recording the lecture, including the use of Replit and video tools.

Conclusion

• Understanding string methods is crucial for manipulating text data in Python.
• Practicing with the provided examples can enhance familiarity with these methods.