Chapter 1: Python Basics

Front 1

Global variable

Back 1

Variables that are declared outside any function, and they can be accessed (used) on any function in the program.

Front 2

Local Variable

Back 2

Variables are declared inside a function, and can be used only inside that function. It is possible to have local variables with the same name in different functions.

Front 3

Object Orientated Programming

Back 3

Is a programming language model organized around objects rather than "actions" and data rather than logic.

*Historically, a program has been viewed as a logical procedure that takes input data, processes it, and produces output data.

Front 4

Shell

Back 4

Is a program that lets you type instructions into the computer, much like the terminal or command prompt.

Front 5

Python Interactive Shell

Back 5

Lets you enter instructions for the python interpreter software to run.

The computer reads the instructions you enter and runs them immediately.

Front 6

Expression

Back 6

Consists of values (such as 2) and operators (such as +) that evaluate (reduce) down to a single line.

*Evaluates to a single value.

Ex: >>> 2 + 2

4

>>>

Front 7

Operators that can be used in Python

Back 7

** : Exponentiation

%: Modulus/remainder

//: Integer division/floored quotient

/: Division

*: Multiplication (can only be used with 2 numeric values or for string replication.)

-: Subtraction

+: Addition

Front 8

Prescedence

Back 8

Order of operations of Python math operators. (PEMDAS)

** operator is evaluated first; the *, /, // and % operators next, and the + and - operators are evaluated last. (From left to right)

Front 9

Data type

Back 9

A category for values, and every value belongs to exactly one _____ type.

Front 10

Common data types in Python

Back 10

-Integers (-2, -1, 0, 1 , 2, 3)

-Floating-point numbers (-1.25, -1.0, -0.5, 0 , 0.5,)

-Strings ("a", "aa", "Hello")

Front 11

Integer (int) Values

Back 11

Data type that indicates values that are whole numbers.

*Helpful if you have a number as a string value that you want to use in some math.

Front 12

Floating-point (float) Values

Back 12

Data type that indicates values with a decimal point.

Front 13

String (str) Values

Back 13

Data type that indicate values with character surrounded by quotes. (' ', " ")

Front 14

Blank string

Back 14

A string with no characters in it.

(' ')

Front 15

String Concatenation

Back 15

When + operator is used to join two string values and combines them together.

Front 16

String Replication operator

Back 16

* operator used on one string and integer value to replicate/repeat the original number of times equal to the integer value.

Ex: 'Alice' * 5

AliceAliceAliceAliceAlice

Front 17

Variable

Back 17

Is like a box in the computer's memory where you can store a single value.

*If you want to use the result of an evaluated expression later in you program, you can save it inside a variable.

Front 18

Assignment Statement

Back 18

Where you store values in variables.

Consists of a variable name, an assignment operator (=) and the value stored.

Ex: spam= 42

Front 19

Overwritting

Back 19

When a variable is assigned a new value, the old one is forgotten. (Variable reassignment??)

Front 20

Variable Names

Back 20

3 Rules:

1. Can only be one word

2. Can only use letters, numbers and the underscore characters.

3. Cannot begin with a number.

* They are case-sensitive and best describes the data it contains.

Front 21

File editor

Back 21

Where you type your code. Similar to text editors like Notepad or TextMate. Has some specific features for typing in source code.

Front 22

Interactive shell vs. File Editor

Back 22

-Interactive shell window will always be the one with the (>>>) prompt.

- The file editor will not

Front 23

#

Back 23

Used to write notes or single lined comments to remind yourself what the code is trying to do.

*Commenting out is when programmers use # character in front of a line of code to temporarily remove it while testing the program to see what works and what doesn't. Then removing the # once they are all set testing.

Front 24

print()

Back 24

Function that displays the string value inside the parenthesis on the screen.

Front 25

Arguement

Back 25

Is a value that is is passed to a function.

Front 26

input()

Back 26

Function waits for user to type in some text on the keyboard and press enter.

This function call evaluates to a string equal to the user's text, and then assigns the string value to a variable.

Always return a string

Front 27

len()

Back 27

Function evaluates to the integer value of the number of characters in that string.

* You can pass this function a string value (or a variable containing a string.)

Front 28

str()

Back 28

Function that can be passed an integer value and will evaluate to a string value version of it.

*Is handy when you have an integer or float that you want to concatenate to a string.

Front 29

Difference between expression and assignment statement

Back 29

One evaluates down to a single line, opposed to having a value stored into a variable.

Front 30

round()

Back 30

Function that returns number rounded to the number digits position after the decimal point.

EX: >>> round(32.45)

32

>>>