Python Data Types Quiz

Python Data Types

• String (str): Text data type represented as a sequence of characters enclosed in single or double quotes.
• Integer (int): Numeric data type representing whole numbers (e.g., 10, -5, 0).
• Float (float): Numeric data type representing decimal numbers (e.g., 3.14, -2.5).
• Complex (complex): Numeric data type representing numbers with imaginary parts (e.g., 2+3j).
• Boolean (bool): Data type representing truth values, either True or False.
• Dictionary (dict): Mapping type where elements are stored as key-value pairs.
• List (list): Mutable sequence type allowing elements to be added, removed, and modified.
• Tuple (tuple): Immutable sequence type where elements cannot be changed after creation.
• Range (range): Sequence type generating a sequence of numbers.
• Set (set): Mutable collection containing unique elements, unordered and cannot contain duplicates.
• Frozen Set (frozenset): Immutable version of a set.
• Bytes (bytes): Immutable sequence of bytes, used for representing binary data.
• Byte Array (bytearray): Mutable sequence of bytes, similar to bytes but can be modified.
• Memory View (memoryview): Object offering a view of memory without copying data.
• None (None): Special data type representing the absence of a value.

String Fundamentals

• A String represents a sequence of characters.
• Strings are enclosed in single quotes ( '...' ) or double quotes ( "..." ).
• Strings can contain letters, digits, and symbols.
• Strings can be concatenated (joined) using the + operator.
• The + operator can be used to join strings.

String Indexing

• Each character in a string has an associated index.
• Indexing starts at 0 for the first character, increasing from left to right.
• Negative indices start from -1, representing the last character, progressing towards the left.
• You can access individual characters within a string using their indices.

String Slicing

• Extracting a portion of a string using a range of indices.
• Syntax: string[start:end:step], where:
  • start: Index of the first character to include (inclusive).
  • end: Index of the first character to exclude (exclusive).
  • step: Number of characters to skip between indices (default is 1).
• Omitting start: string[:end] extracts from the beginning.
• Omitting end: string[start:] extracts to the end.
• Omitting start and end: string[::step] extracts with a specified step.

String Formatting

• Several methods exist for dynamic string formatting:
  • % operator: Uses placeholders like %s for strings, %d for integers, etc., and formats them with a specific pattern.
  • .format()** method:** Employs curly braces {} as placeholders, which are replaced with specified arguments.
  • f-string: Introduced in Python 3.6, prefixes the string with 'f' and directly embeds values within curly braces {}.

String Methods

• Python provides numerous built-in methods for string manipulation, accessed via the . operator:
  • capitalize(): Converts the first character to uppercase, and the rest to lowercase.
  • casefold(): Converts the string to lowercase, considering all case variations.
  • center(length, character): Returns a centered string within a specified length, padded by a given character (defaults to spaces).
  • count(value, start, end): Counts the number of occurrences of a specific value within the string.
  • endswith(value, start, end): Checks if the string ends with a specified value.
  • index(value, start, end): Finds the index of the first occurrence of a specific value within the string.
  • isalnum(): Returns True if all characters are alphanumeric (letters or numbers).
  • isalpha(): Returns True if all characters are alphabetic (letters).
  • isnumeric(): Returns True if all characters are numeric (digits).
  • isspace(): Returns True if all characters are whitespace.
  • istitle(): Returns True if the string follows title case (first letter of each word is uppercase).
  • isupper(): Returns True if all characters are uppercase.
  • islower(): Returns True if all characters are lowercase.
  • join(iterable): Concatenates elements of an iterable (like a list) into a single string, separated by the string.
  • lower(): Converts the string to lowercase.
  • replace(oldvalue, newvalue, count): Replaces occurrences of an old value with a new value.
  • split(separator, maxsplit): Splits the string into a list of substrings, based on a specified separator (default is whitespace).
  • startswith(value, start, end): Checks if the string starts with a specific value.
  • strip(characters): Removes leading and trailing whitespace or specified characters.
  • swapcase(): Swaps the cases of characters (lowercase becomes uppercase, and vice versa).
  • title(): Converts the string to title case (first letter of each word is uppercase).
  • upper(): Converts the string to uppercase.

Escape Characters

• Special characters that represent other characters, often for inserting quotation marks within a string:
  • *: Represents an asterisk.
  • \: Represents a backslash.
  • \”: Represents a double quote.
  • \n: Represents a newline.
  • \t: Represents a tab.

len() function

• Returns the length (number of characters) of a string.
• Works with other iterable objects to count their elements.