import matplotlib.pyplot as plt
"""
DS2000: Programming with Data (Prof. Rachlin)
Lecture 04

TODAY'S TOPICS:

- Visualizing the Collatz Conjecture
- Controlling program flow:
    if
    if..else
    if..elif..else
    if..elif..elif..else
    if..elif..elif..elif..else
    .
    .
    .
    etc.
    while loops.


"""


# ok, new content!
# a big step for us today: conditional statements

# %%
# last time we talked about Boolean variables
print(True)
print(False)
print(2 == 2)
print(2 == 3)
print(2 > 3)
print(2 != 3)

# %%
# there are also 'logical operators' that we can use
print(True and False)
print(True or False)
print(3 == 3 or 2 == 3)
print(not 2 == 2)

# %%
x = 101
print(x > 1 and x <= 100)
print(1 < x <= 100)


# %%
# by themselves, boolean statements may not seem *terribly*
# useful, but they can be used to decide how a program behaves!
# introducing: IF statements!

if True:
    # do something
    print("hi!")

# %%
if 2 + 2 == 4:
    print("Python can do math!")
else:
    print("You better switch to Java!")

# %%

# how about checking if a given number is a multiple of 10?
x = 101
if x % 10 == 0:
    print(x, "is a multiple of 10.")
else:
    print(x, "is *not* a multiple of 10.")

# %%
# note that we can actually leave out the else clause if we like
x=100
if x == 100:
    print("x is 100!")

print("I'm done")


# %%

# one thing we can do with if statements, for example, is check user-input
# or other variables before an operation
x = 100
z = 0


if z != 0:
    ratio = x / z
    print(ratio)
else:
    print("cannot divide by 0!")

print(ratio)


# %%

# let's come back to our hobbies example. as you may recall, we asked
# for exactly three hobbies. how can we check that the user complies?
hobbies = input("input 3 hobbies separated commas: ").split(",")
if len(hobbies) == 3:
    # ...
    print("ok good!")
else:
    print("I said 3!!")


# %%


# but this still assumes they respected comma separation. can we check this as well?
hobby_input = input("input 3 hobbies separated commas: ")
if "," in hobby_input:
    hobbies = hobby_input.split(",")
    if len(hobbies) == 3:
        # ...
        print("ok good!")
    else:
        print("I said 3!!")
else:
    print("I said separated by commas!")

# %%
# sometimes there are multiple "special cases" that we want to treat separately
# for example imagine we have a special message for two users (cathy and bob)
# and a generic one for everyone else
name = input("what is your name? ")

if name == "Bob":
    print("Hi Bob.")
elif name == "Cathy":
    print("Hi Cathy.")
else:
    print("Hello stranger!")

# %% while loops and counting to 10

x = 1
while(x <= 10):
    print(x)
    x += 1

# %% Count forever until you halt the program manually
# Input/Output (I/O) is one of the slowest operations you can perform on a computer!
x = 1
while(True):
    print(x)
    x += 1

#%% Here we are still counting one-by-one, but only printing every millionth
# value to the console

x = 1
while(True):
    if x % 1000000 == 0:
        print(x)
    x += 1