118
edits
Changes
Jump to navigation
Jump to search
→Casting Variables
*int(2.9999) → 2
*int("1964") → 1964
'''Lists'''
In Python a list is indicated by square brackets and commas. Define a list like any other variable, except enclose all the list elements in square brackets and separate them by commas. '''For example: myList = [var1,var2,var3].''' The elements of a given list can be recalled by typing the name of the list followed with the index of the item enclosed in square brackets. '''For example: myListLists[0] ⟶ var1.''' Lists can be modified during runtime with methods such as these:
* myList'''.append('''x''')''' - Adds a new element (x) to the end of the list
* myList'''.remove('''x''')''' - Removes the first item with the specified value (x)
* myList'''.index('''x''')''' - Returns the index of the first element with the specified value (x)
* myList'''.insert('''x''')''' - Adds an element at the specified position (x)
* myList'''.clear()''' - Removes all the elements from the list
<br />
==Methods==
The next major thing to learn about Python is methods. Methods are functions that act upon objects and variables in your code. You can use methods to obtain information about variables/objects or update their values. And the syntax of a method goes as follows:
One of the most important concepts in procedural programming is the loop. Like the name suggests, a loop simply iterates through some selected lines of code a certain amount of times. In Python there are a few different types of loops you can choose from, they are:
#'''While Loop''' - Like the name suggests, a while loop repeats a block of code while a certain expression is true. This kind of loop is useful when we don't know how many times a loop will actually execute at runtime. The While Loop is composed of two parts; the loop statement and the code block to repeat (indented). The syntax looks like this:[[File:While Loop Example.png|thumb|An example of a while loop]]'''<code>while ('''statement'''):''' </code>'''''*code to repeat*'''''<br />The while loop will loop over the code block until the statement in parentheses equates to false. The statement can be an algebraic equation or variable. (ex: (n+1)/4 == 1) <br />[[File:Example For loop.png|thumb|2 examples of for loops that yield the same result. ]]
#'''For Loop''' - This loop will run once for each element in a list. This kind of loop is useful when iterating over loops and arrays or when we know exactly how many times the code block should run. There are two main ways to use the for loop.
##To iterate over a list - Will run the code block once for each element in a list. You can reference the element data during each iteration by putting an element name after "for". Example of this syntax can be seen below: '''for''' element '''in''' list''':''' '''''*code to repeat*''''' <br />
