For & While Loops

What Are Loops?

• Loops are blocks of code that run as long as a condition is true.
• They allow repeating code logic for as long as the condition is true.

For Loops

• Perform blocks of code if the condition is true
• A for loop provides iterating capabilities.
• Can iterate over lists, defined ranges, and more

Range vs. List in Loops

• List iteration allows printing data.
• A set range, defined by range(), is also capable of iteration.
• A variable is defined within the loop as the iterating item.

Calculate Loop Size

• The len() function returns the number of items of an object.
• The range() function accepts an integer and returns the range of the object.

While Loops

• Perform a block of code while a condition is true
• If the condition is false, the while loop will not be executed.
• While loops do not have iteration capability like for loops.

Break Command

• Both for and while loops can be interrupted.
• The break command exits a loop.
• Can be placed strategically for flow control

Continue Command

• Can be used in both for and while loops
• The continue command skips an iteration.
• Behaves as if the code reached the end of the block

Pass Command

• Pass statements are used as empty executions.
• This is useful for when we don't want to execute any code.
• Pass can be used as a placeholder for future code.

Pass vs. Continue

• Pass means move on to the remaining code or loop body.
• Continue forces the loop to begin the next iteration.

Loops & Conditions

Mixing Conditions and Loops

• Conditions have a major role in a loop’s flow control.
• They provide greater flexibility for loops.
• They also ensure more efficient conditional checks and help build a better code writing structure.

Infinite Loops

• A loop becomes infinite if a condition is never false.
• To avoid an infinite loop, the loop must verify the existence of a false condition.

Nested Loops and Lists

• The append() function can be used to define a list within another list.
• append() adds a value to an existing variable.
• Nested lists can be used to arrange data in hierarchical structures.