Python Revision Tour II Flashcards

A comprehensive set of vocabulary flashcards covering basic Python string, list, tuple, and dictionary manipulations, built-in methods, and standard library modules like math, random, and statistics.

String

In Python, a sequence of characters enclosed in quotes that can hold any type of known characters.

Immutable

A characteristic of strings and tuples meaning once they are created, the items or characters within them cannot be changed.

Forward Indexing

A memory location indexing method where the index starts from zero ($0$) and moves from left to right.

Backward Indexing

A memory location indexing method where the index starts from minus one ($-1$) and moves from right to left.

Concatenation ($+$)

The operation of joining two or more strings or lists into one.

Replication ($*$)

An operator that creates multiple copies of a string or repeats the elements of a list a specific number of times.

Membership Operators (in and not in)

Operators that check if a specific character, substring, or value exists within a sequence, returning a Boolean value ($True$ or $False$).

String Slicing

The process of extracting a substring or sub-list using the syntax [start : stop : step], where start is included and stop is excluded.

$ord( )$ Function

A function that takes a single string character and returns its corresponding Unicode number.

$chr( )$ Function

A function that takes an integer representing a Unicode value and returns its corresponding character.

$len()$ Function

A built-in function that returns the total count of elements or characters in a string, list, tuple, dictionary, or set.

Traversing

The process of visiting every character or item in a sequence one by one from the beginning to the end.

$capitalize()$ Method

A string method that converts the very first character to uppercase and all other characters to lowercase.

$title()$ Method

A string method that capitalizes the first letter of every word and converts remaining letters to lowercase, using spaces, hyphens, or quotes as separators.

$count()$ Method

Used to find how many times a specific (case-sensitive) substring or element appears within a larger string or list.

$find()$ Method

A string method that returns the index of the first occurrence of a substring, or $-1$ if the substring is not found.

$index()$ Method

A method used with strings or lists to find the index of the first occurrence of a value; it raises a $ValueError$ if the item is not found.

$isalpha()$ Method

Returns $True$ if a string consists entirely of alphabetic characters (letters).

$islower()$ Method

Checks whether all alphabetic characters in a string are lowercase.

$isdecimal()$ Method

Returns $True$ only for string characters that can be used to form numbers in base $10$ ($0$ through $9$).

$isdigit()$ Method

Returns $True$ for all characters in a string that are digits, including superscripts and subscripts.

$isnumeric()$ Method

Returns $True$ for any numeric representation in a string, including fractions and Roman numerals.

$isspace()$ Method

Checks if a string consists only of whitespace characters such as standard spaces, '\t', '\n', '\v', '\r', or '\f'.

$strip()$ Method

A method used to remove leading and trailing whitespace or specific characters from a string.

$replace()$ Method

A string method that creates a new string by replacing all or a specific count of occurrences of a substring with another.

$join()$ Method

Returns a new string by joining elements of an iterable (like a list or tuple) using a specified string separator.

$partition()$ Method

Splits a string into exactly three parts based on the first occurrence of a separator and returns them as a tuple.

$split()$ Method

Breaks a string into a list of substrings based on a specified delimiter; if no delimiter is specified, it splits by any whitespace.

List

A mutable, ordered sequence data type that allows duplicate items and can contain heterogeneous data types.

$enumerate()$ Function

Returns the index and items from an iterable as a tuple, starting from zero ($0$) or a specified start parameter.

Shallow Copy

A copy created using the $copy()$ method or $list()$ constructor where top-level items are independent, but nested lists remain shared between original and copy.

$eval()$ Function

Evaluates and returns the result of a mathematical expression or data structure given as a string.

$append()$ Method

Adds a single item to the very end of an existing list and modifies it in-place.

$extend()$ Method

Adds multiple elements from an iterable individually to the end of a list.

$insert()$ Method

Adds an element to a list at a specific index by shifting existing items one position to the right.

$pop()$ Method

Removes and returns an item from a list based on an index; defaults to the last item if no index is provided.

$del$ Statement

A Python keyword used to remove items by index/slice or delete an entire variable from memory; it does not return a value.

$clear()$ Method

Removes all items from a list or dictionary, leaving it completely empty.

$sort()$ Method

Arranges list elements in ascending or descending order in-place and returns $None$.

$sorted()$ Function

Takes any iterable and returns a brand-new list containing the elements in sorted order.

$sum()$ Function

Calculates the total of all elements in a numerical list or tuple.

Nested List

A list that contains other lists as its individual elements.

Tuple

An ordered, immutable collection data type that is indexed and allows duplicate values.

Tuple Unpacking

A process that extracts values from a tuple and assigns them to multiple variables in a single line of code.

Dictionary

A mutable, ordered collection of unique key-value pairs where keys must be of an immutable data type.

$.get()$ Method

Accesses a dictionary value by key without crashing; returns $None$ or a specified default value if the key is missing.

$.update()$ Method

A dictionary method used to change or add multiple items at once using another dictionary or iterable of pairs.

$.items()$ Method

A dictionary method that returns a view of key-value pairs as tuples.

$fromkeys()$ Method

Creates a new dictionary from an iterable of keys, assigning each key a specified value or $None$ by default.

$setdefault()$ Method

Returns the value of a key if it exists; if not, it inserts the key with a specified default value and returns that value.

$popitem()$ Method

Removes and returns the last key-value pair from a dictionary as a tuple.

Python Module

A file containing Python code (functions, classes, or variables) that can be imported to improve maintainability and reusability.

$$math.ceil(x)$$

A math module function that always rounds a number up to the nearest whole integer.

$$math.floor(x)$$

A math module function that always rounds a number down to the nearest whole integer.

$$math.fabs(x)$$

Returns the absolute value of a number as a float, stripping away any negative sign.

$$random.randint(a, b)$$

Returns a random integer between $a$ and $b$, inclusive of both endpoints.

$$random.randrange(start, stop, step)$$

Picks one random integer within a range where the stop value is exclusive.

$$statistics.mean()$$

Calculates the average of a collection of numerical data by dividing the sum of all numbers by the count.

$$statistics.median()$$

Identifies the middle value in a sorted dataset; it averages the two center values if the count is even.

$$statistics.mode()$$

Returns the value that appears most frequently in a dataset.