# Every program has the ability to perform actions on a list of
# values. The for loop can be used to do this.

# Each time we go through the loop variable i's value will be
# assigned the next value in our list

for i in [2,4,6,8,10]:
    print("i = ", i)

# We can also have range define our list for us. range(10) will
# create a list starting at 0 and go up to but not include
# the value passed to it.

for i in range(10):
    print("i = ", i)

# We can define the starting and ending value for range
for i in range(2, 10):
    print("i = ", i)

# You can use modulus to see if a number is odd or even
# If we divide an even by 2 there will be no remainder
# so if i % 2 == 0 we know it is true
i = 2
print((i % 2) == 0)

# ---------- PROBLEM : PRINT ODDS FROM 1 to 20 ----------
# Use a for loop, range, if and modulus to print out the odds

# Use for to loop through the list from 1 to 21

for i in range(1, 21):

# Use modulus to check that the result is NOT EQUAL to 0
# Print the odds

    if ((i % 2) != 0):
        print("i = ", i)

# ---------- WORKING WITH FLOATS ----------
# Floating point numbers are numbers with decimal values

your_float = input("Enter a float: ")

# We can convert a string into a float like this

your_float = float(your_float)

# We can define how many decimals are printed being 2
# here by putting :.2 before f
print("Rounded to 2 decimals : {:.2f}".format(your_float))

# ---------- PROBLEM : COMPOUNDING INTEREST ----------
# Have the user enter their investment amount and expected interest
# Each year their investment will increase by their investment +
# their investment * the interest rate
# Print out their earnings after a 10 year period

# Ask for money invested + the interest rate
money = input("How much to invest: ")
interest_rate = input("Interest Rate: ")

# Convert value to a float
money = float(money)

# Convert value to a float and round the percentage rate by 2 digits
interest_rate = float(interest_rate) * .01

# Cycle through 10 years using for and range from 0 to 9
for i in range(10):

    # Add the current money in the account + interest earned that year
    money = money + (money * interest_rate)

# Output the results
print("Investment after 10 years: {:.2f}".format(money))

# ---------- WORKING WITH FLOATS ----------
# When working with floats understand that they are not precise

# This should print 0 but it doesn't
i = 0.1 + 0.1 + 0.1 - 0.3
print(i)

# Floats will print nonsense beyond 16 digits of precision
i = .11111111111111111111111111111111
j = .00000000000000010000000000000001

print("Answer : {:.32}".format(i + j))

# ---------- ORDER OF OPERATIONS ----------
# When making calculations unless you use parentheses * and /
# will supersede + and -

print("3 + 4 * 5 = {}".format(3 + 4 * 5))

print("(3 + 4) * 5 = {}".format((3 + 4) * 5))

# ---------- THE WHILE LOOP ----------
# We can also continue looping as long as a condition is true
# with a while loop

# While loops are used when you don't know how many times
# you will have to loop

# We can use the random module to generate random numbers
import random

# Generate a random integer between 1 and 50
rand_num = random.randrange(1, 51)

# The value we increment in the while loop is defined before the loop
i = 1

# Define the condition that while true we will continue looping
while (i != rand_num):

    # You must increment your iterator inside the while loop
    i += 1

# Outside of the while loop when we stop adding whitespace
print("The random value is : ", rand_num)

# ---------- BREAK AND CONTINUE ----------
# Continue stops executing the code that remains in the loop and
# jumps back to the top

# Break jumps completely out of the loop

i = 1

while i <= 20:

    # If a number is even don't print it
    if (i % 2) == 0:
        i += 1
        continue

    # If i equals 15 stop looping
    if i == 15:
        break

    # Print the odds
    print("Odd : ", i)

    # Increment i
    i += 1

# ---------- PROBLEM : DRAW A PINE TREE ----------
# For this problem I want you to draw a pine tree after asking the user
# for the number of rows. Here is the sample program

'''
How tall is the tree : 5
    #
   ###
  #####
 #######
#########
    #
'''

# You should use a while loop and 3 for loops

# I know that this is the number of spaces and hashes for the tree
# 4 - 1
# 3 - 3
# 2 - 5
# 1 - 7
# 0 - 9
# Spaces before stump = Spaces before top

# So I need to
# 1. Decrement spaces by one each time through the loop
# 2. Increment the hashes by 2 each time through the loop
# 3. Save spaces to the stump by calculating tree height - 1
# 4. Decrement from tree height until it equals 0
# 5. Print spaces and then hashes for each row
# 6. Print stump spaces and then 1 hash

# Get the number of rows for the tree
tree_height = input("How tall is the tree : ")

# Convert into an integer
tree_height = int(tree_height)

# Get the starting spaces for the top of the tree
spaces = tree_height - 1

# There is one hash to start that will be incremented
hashes = 1

# Save stump spaces til later
stump_spaces = tree_height - 1

# Makes sure the right number of rows are printed
while tree_height != 0:

    # Print the spaces
    # end="" means a newline won't be added
    for i in range(spaces):
        print(' ', end="")

    # Print the hashes
    for i in range(hashes):
        print('#', end="")

    # Newline after each row is printed
    print()

    # I know from research that spaces is decremented by 1 each time
    spaces -= 1

    # I know from research that hashes is incremented by 2 each time
    hashes += 2

    # Decrement tree height each time to jump out of loop
    tree_height -= 1

# Print the spaces before the stump and then a hash
for i in range(stump_spaces):
    print(' ', end="")

print("#")