EasyCode Pillars

Python Cheat Sheet

DATA TYPES

Students need to be aware of 4 data types:

  • String ➔ “this is a string” ; you can use either single quotes ‘ ‘ or double quotes ” “
  • Integer ➔ 12 ; an integer is a whole number, such as 12, 0 or -4
  • Float ➔ 3.14 ; a float​ is any number with decimals
  • Boolean ➔ True ; note True and False require a capital T or capital F

Colors in the Codesters text editor are related to type:

  • “strings are green”
  • numbers like 12 or 3.14 are blue
  • Booleans like True and False are red
  • variable names are orange
  • everything else is white including functions, classes, punctuation, and reserved words

 

MATH AND RANDOM (see the Math section of the Toolkit for more)

6 + 3  ➔ 9 addition

633  ​ subtraction

6 * 318 multiplication

6 / 32 division

7 % 31 remainder (modulo)

6 ** 3196 **​ exponent

random.randint(1, 10) ➔ creates a random integer​ between 1 and 10

random.rand() ➔ creates a random float​ (decimal) between 0 and 1

“Hello” + ” world!”Hello world! +​combine two strings

“I am “ + str(13) ➔ I am 13  str( )​ when combining a string and an integer with +

 

VARIABLES

Variables let you store a piece of data to use later. This data can also change over the course of a program, so it’s useful for keeping track of things like scores. To create a variable, just type the name of the variable followed by an equals sign and a value. For example:

  • fav_class = “coding”
  • score = 14

3 rules for naming variables:

1) Do not put variable names in quotes

2) Variable names cannot contain spaces, use underscores _ instead

3) Variable names cannot begin with numbers

For Example:

  • “result” = 12 ; must be ➔ result = 12
  • my name = “Codesters” ; must be ➔ my_name = “Codesters”
  • 3rd_example = True ; must be ➔ third_example = True

 

BLOCKS (If statements, Loops, Functions, and Events)

If Statements​ let you execute or skip a group of commands depending on whether the condition you provide is true or false.

  • For example – this tests whether you guess the correct answer “blue”.

PythonCheatSheet_Codesters-example-blue

  • You can use the following comparisons and logical operations:

==   equal   !=   not equal

>   greater than   >=   greater than or equal to

<   less than   <=   less than or equal to

and      or

Loops​ let you execute a group of commands multiple times.

  • For example – this tells the sprite to count to 5.

PythonCheatSheet_Codesters-example-counter

  • For example – this tells the sprite to say the each letter in “Codesters”.

PythonCheatSheet_Codesters-example-letters

Functions​ let you create a group of commands that you can run later.

  • For example, this function squares a number, says the square, then returns the result.

PythonCheatSheet_Codesters-example-squared

Events ​let you create a group of commands that will run when certain things happen on the stage, or the user presses a particular button.

Whitespace and formatting blocks

  • Python is very​ particular about whitespace. All code inside of these blocks must be indented four spaces.
  • Codesters will highlight the whitespace in these blocks. If your highlighting is missing, check your whitespace.
  • The first line of all these blocks always ends in a colon.