webinar-python-exam-review-2021-03-20

# exam review March 20 2021

# pay special attention to the end of chapter exercises
# Ch 8, 9, 11, 12

# be able to recognize and use common data types
# integers
# floats
# Boolean
# strings
# lists
# tuples
# sets
# dictionaries
# # our modules
# math
# random
# datetime --> datetime.datetime and datetime.timedelta
# os
# calendar
# pandas

# functions
# defining and calling
# parameters vs arguments
# parameters are not like "regular" variables
# return vs print()

# defining the function
def addThese(x, y):
    # x = 3 # don't do this
    # y = 4 # don't do this
    return x + y
# calls to function
print(addThese(1, 2)) # 3 --> to see it, we'll need to print() the call itself
print(addThese(3, 4)) # 7

myVar = addThese(4,5) # because this function returns, it's the same as...
# myVar = 9
print(addThese(4, 5))

# LOOPS repeat actions
# FOR LOOPS repeat for everything in a container
# WHILE LOOPS are like IF statements that keep repeating as long as TRUE
# --> FOR <-- loops are probably more useful on the exam

myList = ["Gilligan", "Scooby", "Agent Scully"]
for item in myList:
    print(item)

scoobies = {
    "Scooby": "a blue collar",
    "Shaggy": "green",
    "Velma": "orange",
    "Daphne": "purple",
    "Fred": "an ascot"
}
for key in scoobies:
    # nameOfDictionary[key] --> retrieve or set the VALUE for that key
    # Scooby wears a blue collar.
    # value = scoobies[key]
    print("{} wears {}.".format(key, scoobies[key]))
# for key, value in scoobies.items():
#     print("{} always wears {}.".format(key, value))

# IF
# if some condition:
# if/elif/else
# if/elif/elif/else

# "MEMBERSHIP CHECK"
myList = ["Gilligan", "Scooby", "Agent Scully"]
if "Mulder" in myList:
    print("Found Mulder in the list.")
else:
    print("No Mulder there.")

# Operators
# +
# -
# *
# /
# # don't forget
# // # floor division
# % # MODULO is more important than you think: what WHOLE NUMBER is left over?
# print(8/3) # 2.66666666
# print(8//3) # 2
# print(8 % 3) # 2
# print(25%4) # 1
largeOz = 38
print("lbs:", largeOz // 16)
print("and oz left over:", largeOz % 16)

# other operators
# = # assignment
# <
# >
# <=
# >=
# == # single = is assignment, double == is asking "are they equal?"
# !=
# += # x += 1 is the same as x = x + 1
# -=
# not

x = 234.134646246224
# myStr = "I am specifying x to 2 decimals: %.2f" % (x)
# print(myStr)
myStr = "I am specifying x to 2 decimals: {:.2f}".format(x)
print(myStr)

# 3 ways to round
# round() # built-in functions
# math.ceil()
# math.floor()

# SLICING
# Be able to slice strings and lists like it's second nature

# STRING methods
# myString = "Hello"
# myString.join() # feed it a list and get a longer string back: ",".join(someListofStrings)
# myString.split() # takes your string and creates a list of substrings
# myString.count() # counts a particular value
# myString.replace() # 2 args: substring to look for, substring to replace it with
# myString.find() # returns first index where substring starts
# myString.strip() # has left and right variants: lstrip(), rstrip()
# myString.lower()
# myString.upper()
# myString.title()
# myString.capitalize()
# myString.isLower()
# myString.isUpper()
# myString.format()

# LIST methods
# myList.append()
# myList.extend()
# myList.insert()
# myList.pop() # by index
# myList.remove() # by value
# myList.count()
# myList.index() # if you know value but not its index: myList.index("Gilligan") --> 0
# myList.sort(reverse=False)
# myList.reverse()

# myList = ["Gilligan", "Scooby", "Agent Scully"]
# # myList.pop(0)
# myList.remove("Gilligan")
# print(myList)


# help(str)
# print(dir(str))

# DATETIME module
# full module import:
import datetime
# partial import:
from datetime import timedelta
# from -module- import -specific thing-
# import with alias:
# import datetime as dat
# each way of importing changes how you refer to the thing later

print(dir(datetime.datetime))
dt = datetime.datetime(2020, 12, 31)
print(dt)
dt = datetime.datetime.today()
print(dt)
dt = datetime.datetime.now()
print(dt)
# strftime see strftime.org
print(dt.strftime("%A"))
print(dt.month)


td = datetime.timedelta(days=10)
print("The delta is:", td)
td.total_seconds() # a method of datetime.timedelta
print(dt + td) # adding a datetime.datetime to a datetime.timedelta


# RANDOM module
import random
# random.randint() # includes stop number, which is unusual in Python
# random.randrange() # excludes stop number, otherwise same as randint()
# random.random() # # returns a float b/n 0 and 1
# random.choice() # picks random item from list or other iterable

# MATH module
# math.floor()
# math.ceil()
# math.sqrt()
# math.pow() # not to be confused with math.exp()
# math.e


# BUILT-IN FUNCTIONS
# print()
# list()
# set()
# dict()
# tuples()
# help()
# dir()
# len()
# sum()
# min()
# max()
# enumerate() # see FOR LOOPS webinar for more on enumerate() and range()
# range()