In Python, it's crucial to understand the difference between an expression and a statement. They are the fundamental building blocks of any Python program.

What is an Expression?

An expression is any piece of code that evaluates to a value. It's a combination of values (like numbers or strings), variables, and operators. When Python encounters an expression, it computes it and reduces it down to a single value.

Think of an expression as a question that Python answers with a value.

• 10 + 5 is an expression. Python evaluates it and produces the value 15.

• 5 * 2 from your Canvas code is an expression that evaluates to 10.

• "Hello" + " " + "World" is an expression that evaluates to the string "Hello World".

• x > 5 is an expression that evaluates to a boolean value, either True or False.

You can think of almost any part of your code that produces a value as an expression.

What is a Statement?

A statement is a complete instruction that performs an action. It's a command that you give to the Python interpreter. Statements do not necessarily evaluate to a value; their purpose is to do something.

Think of a statement as a complete sentence that tells Python what to do.

• Assignment Statement (=): This is the most common type. The line result1 = 10 + 5 * 2 from your Canvas code is a statement. Its action is to first evaluate the expression on the right (10 + 5 * 2) and then assign the resulting value (20) to the variable result1.

• print() Statement: The line print(f"10 + 5 * 2 = {result1}") is a statement. Its action is to display output to the console.

• Control Flow Statements: if statements, for loops, and while loops are all statements that control the flow of a program's execution.

• import Statement: import pandas is a statement that imports a library.

In summary, expressions are evaluated to produce a value, while statements are executed to perform an action. A statement is often composed of one or more expressions.

# --- 1. Understanding Expressions ---

# An expression is anything that evaluates to a value.

print("--- Expressions ---")

# The following are all expressions:

value1 = 10 + 5       # The expression is `10 + 5`, which evaluates to 15.

value2 = 20 * 2       # The expression is `20 * 2`, which evaluates to 40.

value3 = "Hello"      # A literal value like "Hello" is also an expression.

value4 = len("Python") # The function call `len("Python")` is an expression that evaluates to 6.

value5 = 10 > 5       # The comparison `10 > 5` is an expression that evaluates to True.

print(f"The value of the expression '10 + 5' is: {value1}")

print(f"The value of the expression 'len(\"Python\")' is: {value4}")

print(f"The value of the expression '10 > 5' is: {value5}")

# --- 2. Understanding Statements ---

# A statement is a complete instruction that performs an action.

print("\n--- Statements ---")

# The entire line is a statement. It tells Python to assign a value.

# The part on the right side of '=' is an expression.

x = 10

print("`x = 10` is an assignment statement.")

# An `if` block is a statement. It controls the flow of the program.

# The `x > 5` part inside it is an expression.

if x > 5:

    # This print() call is also a statement inside the if block.

    print("`if x > 5:` is a conditional statement, and it was executed.")

# A `for` loop is a statement. Its action is to iterate over a sequence.

# `range(3)` is an expression that creates a range object.

print("\n`for i in range(3):` is a loop statement:")

for i in range(3):

    # This print() is a statement that is executed in each loop iteration.

    print(f"  Loop iteration {i}")

# A function definition is a statement.

def my_function():

    # This is a statement inside the function.

    print("This is a function statement.")

# Calling a function is an expression, but the line itself is a statement.

my_function()

# --- 3. Statements Containing Expressions ---

# Most statements contain expressions.

# The statement is the entire line.

# The expression is `(20 + 30) / 5`.

final_result = (20 + 30) / 5

print(f"\nThe statement `final_result = (20 + 30) / 5` assigned the value {final_result}.")