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

# In[7]:


# Boolean variables
# can assign the True and False values to variables
hungry=True
sleepy=False
# Recall that x<y returns True or False
# Example:
x=5
y=6
print("type(x<y) is",type(x<y))
print("x<y is",x<y)

# Test the variables hungry and sleepy:
print("hungry is",hungry)
print("type(hungry) is",type(hungry))
print("sleepy is",sleepy)
print("type(sleepy) is",type(sleepy))
if hungry:
    print("I am hungry.")
if sleepy:
    print("I am sleepy.")
else:
    print("I am not sleepy.")


# In[11]:


# Section 4.1 -- Repetition Structures
# Consider the following code:

#Get person1's sales and commission rate
sales1=float(input("What were Person1's sales this month?"))
comm_rate1=float(input("What is Person1's commission rate?"))
commission1=sales1*comm_rate1
print("Person 1 got a commission of $",commission1,sep='')

#Get person2's sales and commission rate
sales2=float(input("What were Person2's sales this month?"))
comm_rate2=float(input("What is Person2's commission rate?"))
commission2=sales2*comm_rate2
print("Person 2 got a commission of $",commission2,sep='')

# Imagine there are 10-20 people that this code needs to be copied for.
#
# That code would be greatly simplified with a repetition structure
# also known as a "loop"
#
# Two kinds of loops as defined by the book:
#    1. condition controlled loop
#    2. count controlled loop


# In[15]:


# Section 4.1: while loops
# these are condition-controlled loops
#
# syntax
# while condition:
#     stuff
#     stuff
#     etc
#
#
#############
# Importatnt fact: while loops check the condition before acting
# Redo the commission example from earlier:
keep_going=True
while keep_going:
    sales=float(input("What are the person's sales?"))
    comm_rate=float(input("What is the person's commission rate?"))
    commission=sales*comm_rate
    print("This person's commisssion is $",commission,sep='')
    stop_or_not=input("Enter y if you want to compute another commission, enter n if you do not.")
    if(stop_or_not=='n'):
        keep_going=False
        
# The while loop is a "pretest" loop, meaning it
# checks the condition before it does anything.
# There are repetition structures that do a thing
# before checking a condition -- we will see later.


# In[19]:


# Employer needs a program to direct an employee at a
# chemical facility. The temperature of a vat needs to be
# checked every 15 minutes. If temperature in degrees
# Celsius does not exceed 102.5 degrees, then do nothing. If
# the temperature exceeds 102.5, then turn down termostat and
# check again in 5 minutes.
CUTOFF_TEMP=102.5
current_temp=float(input("What is the current temperature reading?"))

while(current_temp>CUTOFF_TEMP):
    print("Turn down the thermostat and then take another temperature reading in 5 minutes.")
    current_temp=float(input("What is the current temperature reading?"))
print("Run this program again in 15 minutes.")


# In[21]:


# Quintessential infinite loop
#while 1>0:
#    print("never stop!")