# ============================================================
#  LESSON 2 — Conditional Execution
#  Based on: Python for Everybody (PY4E) by Dr. Chuck Severance
#  Video: https://www.youtube.com/watch?v=8DvywoWv6fI  (1:26:00 – 1:52:48)
#
#  Read the theory on the lesson page first, then work
#  through each section here and run the world to see output.
# ============================================================


# ============================================================
# SECTION 1 — Boolean Expressions
# ============================================================

print(5 == 5)   # True
print(5 != 3)   # True
print(3 < 5)    # True
print(5 > 3)    # True
print(3 <= 3)   # True
print(4 >= 5)   # False

# TASK: Change the values above and predict what each line will print
#       before you run it.


# ============================================================
# SECTION 2 — The if Statement
# ============================================================

x = 10

if x > 5:
    print("x is greater than 5")

print("this always runs")

# TASK: Change x to 3 and run the world again. Notice which line is skipped.


# ============================================================
# SECTION 3 — if / else
# ============================================================

age = 16

if age >= 18:
    print("You can vote.")
else:
    print("You are too young to vote.")

# TASK: Change age to 18, then to 21. Run after each change.


# ============================================================
# SECTION 4 — if / elif / else
# ============================================================

score = 72

if score >= 90:
    print("Grade: A")
elif score >= 80:
    print("Grade: B")
elif score >= 70:
    print("Grade: C")
elif score >= 60:
    print("Grade: D")
else:
    print("Grade: F")

# TASK: Change score to 85, then 55, then 90. Run after each change.


# ============================================================
# SECTION 5 — Logical Operators
# ============================================================

age    = 20
has_id = True

if age >= 18 and has_id:
    print("Entry allowed.")
else:
    print("Entry refused.")

# TASK: Set has_id to False and run again.
#       Then change the 'and' to 'or' — what is different?


# ============================================================
# SECTION 6 — try / except
# ============================================================

raw = await input("Enter a number: ")

try:
    number = int(raw)
    print("You entered:", number)
except:
    print("That was not a valid number.")

# TASK: Run the world twice — once typing a number, once typing a word.
#       Notice how try/except stops the program from crashing.


# ============================================================
# SECTION 7 — Exercise
# ============================================================
# Write a program that:
#   1. Asks the user to enter a temperature in Celsius
#   2. Uses try/except to catch invalid input
#   3. If the input is valid, print one of these messages:
#        Below 0  -> "Freezing"
#        0 to 15  -> "Cold"
#        16 to 25 -> "Mild"
#        26 to 35 -> "Warm"
#        Above 35 -> "Hot"
#
# Expected output (if the user types 22):
#   Mild

# Write your solution here: