#!/usr/bin/env python
# coding: utf-8

# In[11]:


# Section 3.1 - if statements
# idea: control flow by asking a yes or no question and 
#       doing "stuff" if the answer is "yes" and not doing "stuff"
#       if the answer is "no"
#
# Syntax in Python
# if condition:
#     stuff
#     more stuff
#     more more stuff
#
#  we will see later an example
#
# How do we specify a condition?
#
# Relational operators
# Operator               Meaning
#     >                  greater than
#     <                  less than
#    >=                  greater than or equal to
#    <=                  less than or equal to
#    ==                  (mathematically) equal <-- note "variable assignment"
#                                                   is a different concept
#                                                   from "equals"
#    !=                  not (mathematically) equal
#
#
# Expression           Meaning
#   x < y              "Is x less than y?"
#   x > y              "Is x greater than y?"
#   x<=y               "Is x less than or equal to y?"
#   x>=y               "Is x greater than or equal to y?"
#   x==y               "Is x equal (mathematically) to y?"
#   x!=y               "Is x NOT equal (mathematically) to y?"
#
# Test this out
x=1
y=0
print("x>y is",x>y)
print("x<y is",x<y)
z=1.0
print("x<=z is",x<=z)
print("x<z is",x<z)
print("x==z is",x==z)
print("x!=y is",x!=y)
# Can we make these say "Yes" and "No" instead of "True" and "False"?
# I think no -- because of "bool" type:
# it turns out that x<y has a new type we have never seen:
print("the type of x<y is",type(x<y))


# In[26]:


# Program: take three test scores and average them
#          then write a response to the user saying if they 
#          had a score of >85% encouragement and if htey had
#          an average score of <60% tell them they need to do better.
#
# Make the cutoff scores as named constant
LOW_AVG=60
HIGH_AVG=85
# Ask the user for three test scores: 
# cant forget to typecast as float
score1=float(input("What is the score on the first exam?"))
score2=float(input("What is the score on the second exam?"))
score3=float(input("What is the score on the third exam?"))
# compute the average
average=(score1+score2+score3)/3
# implement the decision structures
print("Your average test score is",average)
# question: how do we tell it to throw out impossible scores?
if average>100:
    print("I think you made a mistake in inputting your grades.")
if average>HIGH_AVG:
    print("Great job! Keep it up!")
if average<LOW_AVG:
    print("You need to practice.")


# In[31]:


# Section 3.2 - if-else statements
# This allows stuff to be done when a condition is false, unlike a pure
# if statement which only does stuff when the condition is true.
#
# Syntax
# if condition:
#     stuff
#     more stuff
#     more more stuff
# else:
#     other stuff
#     other other stuff
#
# If temp<40, print "it is cold", otherwise print "it is nice".
# magic number -- cutoff of temp:
EDGE_TEMPERATURE=40
# get the temperature
temperature=float(input("What is the temperature?"))
if(temperature <= EDGE_TEMPERATURE):
    print("It is cold.")
else:
    print("It is nice.")


# In[33]:


# Overtime calculator
# overtime cutoff (in hours)
OVERTIME_CUTOFF=40
OVERTIME_MULTIPLIER=1.5
# Get the number of hours worked
hours=int(input("How many hours did you work?"))
payrate=float(input("What is your hourly pay rate?"))

if(hours>OVERTIME_CUTOFF):
    overtimehours=hours-OVERTIME_CUTOFF
    totalpay=OVERTIME_CUTOFF*payrate+OVERTIME_MULTIPLIER*overtimehours*payrate
else:
    totalpay=hours*payrate
print("You earned $",totalpay,".",sep='')