Part 01 : Intro to Python

Keep in mind

1.Python is case sensitive.
2.Spacing is important.
3.Use error messages to help you learn.

Lesson 2: Data Types and Operators

Lesson 3: Control Flow

Lesson 4: Functions

Lesson 5: Scripting

Lesson 2: Data Types and Operators

Data Types: Integers, Floats, Booleans, Strings, Lists, Tuples, Sets, Dictionaries
Operators: Arithmetic, Assignment, Comparison, Logical, Membership, Identity
Built-In Functions, Compound Data Structures, Type Conversion
Whitespace and Style Guidelines

01. Introduction

02. Arithmetic Operators

+ Addition
- Subtraction
* Multiplication
/ Division
% Mod (the remainder after dividing)
** Exponentiation (note that ^ does not do this operation, as you might have seen in other languages)
// Divides and rounds down to the nearest integer
Bitwise operators are special operators in Python that you can learn more about https://wiki.python.org/moin/BitwiseOperatorsif you'd like.

03. Quiz: Arithmetic Operators

04. Solution: Arithmetic Operators

05. Variables and Assignment Operators

mv_population = 74728

Here mv_population is a variable, which holds the value of 74728. This assigns the item on the right to the name on the left, which is actually a little different than mathematical equality, as 74728 does not hold the value of mv_population.

x = 3
y = 4
z = 5

x, y, z = 3, 4, 5

You can’t use reserved words or built-in identifiers

my_height = 58
my_lat = 40
my_long = 105

my height = 58 ❎
MYLONG = 40 ❎
MyLat = 105 ❎

The pythonic way to name variables is to use all lowercase letters and underscores to separate words.

You can find some practice with much of what we have already covered ：https://www.programiz.com/python-programming/operators

06. Quiz: Variables and Assignment Operators

4.445e8 is equal to 4.445 * 10 ** 8 which is equal to 444500000.0.

07. Solution: Variables and Assignment Operators

08. Integers and Floats

int - for integer values
float - for decimal or floating point values

x = int(4.7)   # x is now an integer 4
y = float(4)   # y is now a float of 4.0

>>> print(type(x))
int
>>> print(type(y))
float

print(0.1 + 0.1 + 0.1)
0.30000000000000004

print(0.1 + 0.1 + 0.1)
False

Because the float, or approximation, for 0.1 is actually slightly more than 0.1, when we add several of them together we can see the difference between the mathematically correct answer and the one that Python creates.

https://docs.python.org/3/tutorial/floatingpoint.html

Python Developer's Guide: https://www.python.org/dev/peps/pep-0008/

09. Quiz: Integers and Floats

In general, there are two types of errors to look out for https://docs.python.org/3/tutorial/errors.html

Exceptions
Syntax

10. Booleans, Comparison Operators, and Logical Operators

True - 1
False - 0
< > <= >= == !=
and or not

11. Quiz: Booleans, Comparison Operators, and Logical Operators

12. Solution: Booleans, Comparison and Logical Operators

13. Strings

>>> my_string = 'this is a string!'
>>> my_string2 = "this is also a string!!!"


>>> this_string = 'Simon\'s skateboard is in the garage.'
>>> print(this_string)
Simon's skateboard is in the garage.

>>> first_word = 'Hello'
>>> second_word = 'There'
>>> print(first_word + second_word)

HelloThere

>>> print(first_word + ' ' + second_word)

Hello There

>>> print(first_word * 5)

HelloHelloHelloHelloHello

>>> print(len(first_word))

5

>>> first_word[0]

H

>>> first_word[1]

e

len() is a built-in Python function that returns the length of an object, like a string. The length of a string is the number of characters in the string. This will always be an integer.