webinar-python-exam-review-2021-05-15

# Webinar: Exam Review

# Ch 8, 9, 11 and 12 are critical. And structured a lot like the Pre and OA questions

# Be able to recognize your common data types and modules
# integers
# floats
# strings
# lists
# dictionaries
# sets
# tuples
# # modules
# math
# random
# datetime
# calendar
# pandas
# os

# OPERATORS
# + # addition or string concatenation
# -
# *
# /
# // # floor division
# % # gets us the WHOLE NUMBER REMAINDER, how many didn't fit

# how tall is 75 inches?
print(75 // 12, "feet and")
print(75 % 12, "inches")

# = # assigns a value, thus the assignment operator
# == # is for asking if 2 values are equal, the equality operator
# <
# >
# <=
# >=
# !=
# not
# += # x += 1 is the same as x = x + 1
# -=

# STRUCTURES, CONTROL FLOW

# FUNCTIONS
# defining vs calling
# parameters vs arguments
# parameters don't get assigned like regular variables
# the call (each call) gives a parameters its value
# return vs print()
# type methods are themselves functions - look for whether they return values

# IF statements... including IF/ELSE, IF/ELIF/ELSE, IF/ELIF/ELIF/ELSE

# LOOPS
# WHILE - basically an IF that repeats if the condition stays TRUE
# FOR - tied to a container (list, tuple, string, etc), to do something once for each entry
# for _loopVar_ in __container__:
# for item in myList:
# for char in myString:
# for i range(0, 5):

# "membership check"
myList = ["Agent Scully", "Agent Mulder", "Walter Skinner", "CSM", "Mr. X"] # X-Files characters
# if "Agent Mulder" in myList:
print("Agent Scully" in myList) # True
print("Gilligan" in myList) # False

# Be able to SLICE like it's second nature

# BUILDING UP larger STRINGS
x = "Sue"
greeting = "How do you do?"
# CONCATENATION with +
myString = "My name is " + x + ". " + greeting

# DATA CONVERSION i.e. "STRING MODULO"
myString = "My name is %s. %s" % (x, greeting)

# STRING method .format()
myString = "My name is {}. {}".format(x, greeting)
print(myString)

# The big DATA TYPES and their METHODS
# STRINGS
# myString.format()
# myString.split()
# myString.join()
# myString.find()
# myString.replace() # remove
# myString.isupper() and myString.islower()
# myString.upper() and myString.lower(), myString.title(), myString.capitalize()
# myString.strip() and myString.lstrip(), myString.rstrip()
# myString.count()

# LISTS
# myList.pop() # deletes from end, or by index
# myList.remove() # deletes by value
# myList.append() # adds value to end
# myList.insert() # adds value to specific index position
# myList.sort() # sort has a keyword parameter of REVERSE, set to false by default
# myList.reverse()
# myList.count()
# myList.index()
# myList.copy()
# myList.clear()

# DICTIONARIES { : }
beatlesDCT = {
    "Lead Guitar": "George",
    "Rhythm Guitar": "John",
    "Bass": "Paul",
    "Drums": "Ringo"
}
# myDict[key] --> retrieve the value for that key
# myDict[key] = new value       # this even works if the key isn't there, for new k/v
# beatlesDCT.items() # if you're looping and want a separate variable for the value
# beatlesDCT.get()
# beatlesDCT.update() # takes another dictionary as arg
#
# #  SETS { }
# mySet.add()
# mySet.remove()
# mySet.pop()
# mySet.discard()

# TUPLES  ( )
# are really IMMUTABLE
# don't even worry about their methods

# MODULES

# MATH
# math.sqrt()
# math.pow() # not be confused with math.exp()
# math.e # logarithmic constant
# math.pi
# math.floor() # always rounds down
# math.ceil() # always rounds up

# RANDOM
# random.random() # returns a float between 0 and 1
# random.choice() # returns a random value from a list
# random.randint() # range INCLUSIVE of the stop number
# random.randrange() # range that EXCLUDES the stop number

# DATETIME
import datetime
print(dir(datetime))
# datetime.datetime # represents a point in time
# datetime.timedelta # represents a difference in time, a period of "2 weeks" "5 days"
# datetime.datetime(year, month, day)
# datetime.datetime.today() # or datetime.datetime.now()
# datetime.datetime.day
# datetime.datetime.month
# datetime.datetime.year
# datetime.datetime.hour

# datetime.timedelta() requires KEYWORD ARGS
td = datetime.timedelta(days=3) # weeks=0, days=0, hours=0, etc...
datetime.timedelta(weeks=52).total_seconds()
td.total_seconds()

# OS
import os
# os.getcwd()
# os.listdir()
# if it's not at the top of os, it's probably in os.path
# os.path.basename()
# os.path.dirname()
# os.path.isfile()
# os.path.isdir()
# print(dir(os.path))

# a note on IMPORTS
import datetime # normal, total import
from datetime import timedelta # PARTIAL import, so now I say timedelta, not datetime.timedelta
import random as r # ALIAS import, now it's not random.choice(), it's r.choice()

# BUILT IN FUNCTIONS
# print()
# help()
# dir()
# len()
# min()
# max()
# sum()
# range()
# str() # ''
# list() # []
# dict() # {}
# tuple() # ()
# set()
# int()
# float()
# round() # as opposed to math.floor() and math.ceil()
# enumerate()
# open() # working with files in Ch 12
# type()

print(type(myList)) # shows data type/class