1. Training Up: Intro to Python
Nicole Lama

2. Overview Applications of Python Essential Programming Terms
Python Syntax
Basics in Python

3. Python First Introduced in 1990 by Guido van Rossum
Popularized in 2004 by Google
Pros: user-friendliness, readability, generalizability

4. Python Applications include: Statistical Analysis Data Mining
Software Development
Data Visualization
Machine Learning
and more!

5. Python Cons: Can be slow (integration with C speeds things up)
Relative to other programming languages, debugging can be more time consuming

6. Programming Terms
Data Types – integers (2), strings (“Jane”), floats (2.2), Boolean(True or False)
Operators – +, -, <, >, ==, and, or, is, not,!

7. Programming Terms
Data Structures – Things that can store data/information
List, Array
Dictionaries, HashMaps
Trees
Queues, Stacks
Blockchain

8. Lists List = [element0, element1, …, elementn]
Access : List[0] will output the first element
List[n] will output the nth element
List = [“Shalini”, 2, True]
Can contain different data types!

9. Dictionaries Dictionary = {Key : Value}
Access : Dictionary[Key] = Value
Dict = {“Nikhita”: 24, “Joseph”: 18}
Dict[“Nikhita”]
output: 24

10. Programming Terms
Variable – an object you can store data into, and access later. Use camelCase or under_scores
Function – a callable routine which may return a value. Useful for repeating procedures many times
Argument – a variable, or data, accepted by function
Library – an outside collection of functions. Useful so you don’t have to write your own functions.

11. Programming Terms
Commenting – # or ‘’’. Useful for leaving notes or instructions. Will not be read by Python
Errors – Indicative of bugs in your code. Usually cause your script to crash.
Warnings – Indicative of some issue with your code but typically will not crash your script
Ex: DeprecationWarnings, RunTimeWarnings

12. Python Syntax Variable
Var = “a unit that stores data types/information”
Ex:
Num = 3
Str = “Hello!”
Flt = 3.3
*Variable names can be anything you want!!

13. Python Functions
func() will print out whatever you feed it as an argument
Def func(a):
Print(a) Identations matter in Python!
#call your function after defining it
func(“Hi!”) Calling your function like this will print “Hi!”

14. Python Functions Function with return: Def func(a):
Print(a)
return 1
If return is used, make sure to assign variable to “catch” your value. Return will end your function.
catchValue is now equal to 0
catchValue = func(“Hello”)

15. Python Syntax
Argument: input for your function to do work on
Func(a)

16. Python Syntax Library: package with useful functions you can use
import numpy or
import numpy as np
from numpy import add

17. Python Syntax
Comments: useful for adding notes or instructions in code. Not read by Python.
# This is a comment
‘’’ This is a longer comment
that spans multiple lines ‘’’

18. Common Python Errors Syntax Error : missing “, ‘ , or : ?
Missing Indentation error
List index out of range: Tried to access an element that exceeds list size
Segmentation Fault: You ran out of memory. Happens with For and While loops on occasion
Keyword error: happens when trying to access a non existing key in a dictionary

19. Common Python Errors NameError: Variable was called but never assigned
TypeError: Check your datatypes
E.g. Don’t’ do math operations on strings

20. Fixing Python Errors Traceback (most recent call last):
Tells you where your bug is
Traceback (most recent call last):
File "C:/Users/nicol/Desktop/IntroToPython.py", line 122, in <module>
blah
NameError: name 'blah' is not defined
Will tell you error type. Variable was never defined in this case

21. Python Built-In Functions
Useful tools that the developers included in Python to make your life easier

22. Python Built-In Functions
Print(*objects)
Purpose: display value of something
Argument : Any variable, or data type
Returns: nothing

23. Python Built-In Functions
Functions to transform data types:
Int(obj)
Float(obj)
Str(obj)
List(obj)

24. Python Built-In Functions : String Methods
Methods specifically made for strings
Super useful for manipulating any data
All return a modified string
Ex: “hello!”. capitalize()

25. Python Built-In Functions : String Methods
str.upper()
str.lower()
str.capitalize()

26. Python Built-In Functions : String Methods
“sep”.join(iterable)
Purpose: will join together a list of things into one string
Ex: “-”.join([“Built”, “In”])
output: “Built-In”
* Sep can be any separator: commas, periods, dashes, even words!

27. Python Built-In Functions : String Methods
str.replace(replaceMe,withThis)
Replace anything in a string with something else
Ex: “I can’t do it”.replace(“can’t”, “can”)
output: I can do it

28. Python Built-In Functions : String Methods
str.split(sep)
Purpose: will split a string into a list
Ex: “Rose, Lilac, Daisy”.split(“,”)
output: [“Rose”, “Lilac”, “Daisy”]

29. Python Built-In Functions : String Methods
str.strip()
What we see: “ I’m a sentence! ”
What Python sees: “\tI’m\sa\ssentence\s\s\s\s”

30. Python Built-In Functions : String Methods
str.strip()
Purpose: Get’s rid of white space in a string
Ex: “ I’m a sentence! ”.strip()
output: “I’m a sentence!”

31. Python Built-In Functions : List Methods
list. append()
list. extend()
list. count()
list. pop()
list. reverse()
list. clear()

32. Python Built-In Functions : Dictionary Methods
dict. values()
dict. keys()
dict. get()

33. Python Built-In Functions : Reading External Files
inFile = open(“C:\Users\nlama\example.txt”)
do stuff with inFile
inFile.close()

34. Programming Terms
If Statements- Do something only if a condition is met
For Loops- To repeat something a certain amount of times
While Loops- To repeat something until a condition is met

35. Python Operators +,-,%,* : Math operators == : is equal to
<, > : less than, greater than
<= : less than or equal to
! : is not
is, not:
and, or: logical operators

36. Python Operators
8 <= 9
Output: True
8 is not 9
8 != 9

37. Python Syntax If statement x = 0 if (x < 0):
print("Negative number")

38. Python Syntax For loop numbers = [1,2,3,4] for (num in numbers):
print(num*2)

39. Python Syntax While loop i = 0 while(i < 6 ): print(i) i=i+1
*i=i+1 is the same as i+=1

40. Additional Info Popular Libraries in Python: -numPy : General Math
-pandas : Dataset Manipulation
-sklearn, sciPy: Statistics
-matplotlib, seaborn, bokeh : Data visualization
-random : Random number gen, Distributions
-sys, os, csv : Accessing and Reading files

41. Additional Info When to indent in Python:

42. Additional Info https://www.w3schools.com/python/python_intro.asp