Python Data Structures PDF

way of organizing data so that it can be accessed more efficiently -- **Data Structure** That organize and group data according to type -- **Container** a collection which is ordered, changeable, and allows duplicate members -- **List** a collection which is ordered, unchangeable, and allows dupl...

way of organizing data so that it can be accessed more efficiently -- **Data Structure** That organize and group data according to type -- **Container** a collection which is ordered, changeable, and allows duplicate members -- **List** a collection which is ordered, unchangeable, and allows duplicate members -- **Tuple** a collection which is unordered, unchangeable, unindexed and does not allow duplicate members items are unchangeable, but items can be added or removed -- **Set** a collection which is ordered, changeable, and does not allow duplicate members -**Dictionary** just like the arrays declared in other languages, which is an ordered collection of data − very flexible because it can contain different data types -- **List** Adds an element at the end of the list -- **append()** Removes all the elements from the list -- **clear()** Returns a copy of the list -- **copy()** Returns the number of elements with the specified value -- **cout()** Add the elements of a list (or any iterable), to the end of the current list -- **extend** Returns the index of the first element with the specified value -- **index** Adds an element at the specified position -- **insert** Removes the element at the specified position -- **pop** Removes the item with the specified value -- **remove** Reverses the order of the list -- **reverse** Sorts the list -- **sort** a collection of Python objects like a list but are immutable in nature -- **Tuple** Returns the number of times a specified value occurs in a tuple -- **cout** Searches the tuple for a specified value and returns the position of where it was found -- **index** an unordered collection of data that is immutable and does not allow any duplicate element − used to include membership testing and eliminating duplicate entries − can contain different data types -- **Set** Adds an element to the set - **add()** Removes all the elements from the set - **clear()** Returns a copy of the set - **copy()** Returns a set containing the difference between two or more sets - **difference()** Removes the items in this set that are also included in another, specified set -**difference\_update()** Remove the specified item - **discard()** Returns a set, that is the intersection of two other sets - **intersection()** Removes the items in this set that are not present in other, specified set(s)-**intersection\_update()** present in other, specified - **set()** Remove the specified item -- **discard()** Returns whether two sets have a intersection or not - **isdisjoint()** Returns whether another set contains this set or not - **issubset()** Returns whether this set contains another set or not - **issuperset()** Removes an element from the set -- **pop()** Removes the specified element -- **remove()** Returns a set with the symmetric differences of two sets - **symmetric\_difference()** inserts the symmetric differences from this set and another **symmetric\_difference\_update()** Return a set containing the union of sets -- **union()** Update the set with the union of this set and others -- **update** An ordered collection of data values − holds the key:value pair key - an object which can never change like strings, numbers, tuples, etc. − cannot have two items with the same key -- **Dictionary** Removes all the elements from the dictionary -**clear()** Returns a copy of the dictionary -- **copy()** Returns a dictionary with the specified keys and value -- **fromkey()** Returns the value of the specified key -- **get()** Returns a list containing a tuple for each key value pair - **items()** Returns a list containing the dictionary\'s keys - **keys()** Removes the element with the specified key -- **pop()** Removes the last inserted key-value pair -- **popitem()** Returns the value of the specified key. If the key does not exist: insert the key, with the specified value - **setdefault()** Updates the dictionary with the specified key-value pairs **- update()** Returns a list of all the values in the dictionary -- **values()** used to declare a block − if the statements are on the same level of indentation, then they are on the same block -- Identation used to test a specific condition, if the condition is true, a block of code (if-block) will be executed − condition can be any valid logical expression -- **if Statement** if the condition in the if statement is false, it will execute the else statement -- **If-else Statement** checks multiple conditions and executes the block of code of the condition that evaluated to true − optional like else − can contain multiple elif after an if -- **Elif statement** allows the use of another if statements inside an if - **Nested** used for iterating on a sequence (either a list, a tuple, a dictionary, a set, or a string) − a set of statements may be executed once for each item, tuple, set, etc. − does not require an indexing variable to set beforehand -- **For** loop Can stop the loop before it has looped through all the items -- **Break Statement** can stop the current iteration of the loop, and continue with the next -- **Continue Statement** returns a sequence of numbers from 0 and increments by 1, by default, and ends at a specified number -- **range()** block of statements to be executed when the loop is finished cannot be executed if the loop is stopped by a break statement - **else in for Loop** a loop inside a loop − the inner loop will be executed once per iteration of the outer loop -- **nested loop** for loop cannot be empty -- **pass()** as long as the condition is true, it can execute a block of statements − needs to define an indexing variable increment/decrement this variable or the loop will not end -- **while loop** the loop can be stopped even if the while condition is still true - **break** stop the current iteration and continue with the next **- continue Statement** can run a block of code when the condition is no longer true - **else Statement** can run at least once − Python does not have a built-in do-while loop but possible to emulate - **do-while Loop** tests if a condition is true or false and returns the corresponding value, all in one line of code - **Conditional Operator** used to combine conditional statements -- **and or** used to reverse the result of the conditional statement -- **not** keyword used to define a function -- **def** information passed into a function − specified after the function name and inside the parentheses − separated by a comma - **Arguments or args** variable inside the parentheses in the function definition - **parameter** value sent to the function when called -- **argument** order of arguments does not matter -- **kwargs** function calls itself specifies the region where a variable can be accessed o local o global o nonlocal -- **recursion** created inside the add num function and can only be accessed within (local) -- **sum** keyword to create nonlocal variables o used in nested functions when local scope is not defined -- **nonlocal** Python has a built-in random module that can be used to generate random numbers -- a small anonymous function − can take any number of arguments, but can only have one expression - **Random Number** lambda arguments : expression - syntax