Python
The for Loop and range()
A Python for loop walks over the items of a collection directly. range() supplies numbers when you genuinely need a counter, which is less often than...
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Python
The while Loop
while repeats for as long as a condition holds. Use it when the number of repetitions is unknown, and make sure something inside the loop can make the...
Python
Loop Control: break, continue, pass and else
break leaves a loop, continue skips to the next iteration, pass does nothing, and the loop else runs only when no break happened.
Python
Pattern Programming with Nested Loops
Printing shapes with loops teaches nested iteration better than any explanation. Every pattern comes from the same three questions.
Python
Python Lists: Creating, Indexing and Slicing
A list is an ordered, changeable sequence that can hold anything. Indexing, slicing and slice assignment cover most of what you will ever do with one.
Python
List Methods: Adding, Removing and Sorting
Most list methods change the list in place and return None. Knowing which ones return a value and which do not prevents the most common list bug.
Python
Nested Lists, Copying and List Patterns
Lists of lists model grids and tables, copying them needs care, and a handful of patterns cover most real list work.
Python
Python Tuples: Immutable Sequences
A tuple is a list that cannot change. That single restriction makes it usable as a dictionary key, safe to share, and the natural way to return severa...
Python
Tuple Unpacking and Multiple Assignment
Unpacking pulls a sequence apart into names in one statement. It powers swapping, loops over pairs, multiple return values and the star syntax.
Python
Python Sets: Unique Unordered Collections
A set stores unique values with no order and answers membership questions almost instantly. That trade - lose order, gain speed and uniqueness - is th...
Python
Set Operations: Union, Intersection and Difference
Four operations answer four everyday questions: what is in either, what is in both, what is only in the first, and what is in exactly one.
Python
Python Dictionaries: Keys, Values and Lookup
A dictionary maps keys to values and finds any value in roughly constant time. It is the most used container in Python and the structure most real dat...