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Introduction to Python
course content

Course Content

Introduction to Python

Introduction to Python

1. First Acquaintance
The Very First StepsCommentsSome Simple MathMore Challenging MathChallengeBringing It All Together
2. Variables and Types
Storing NumbersNaming RulesUsing VariablesData TypesNumbersChallengeStoring TextString IndexingNegative Indexing and LengthString SlicingChallengeConcatenation
3. Conditional Statements
Boolean Data TypeChallenge: Comparison OperatorsCombining ConditionsChallenge: Logical OperatorsMembership Operators and Types ComparisonSimple if/else ExpressionsChallenge: Grocery StoreChallenge: Odd and Evenif/elif/else ExpressionsChallenge: Grocery Store ExtendedChallenge: Positive, Negative or Zero
4. Other Data Types
What Is a List?List MethodsChallengeNested ListsChallengeWhat Is a Tuple?Tuple MethodsChallengeNested TuplesChallengeWhat Is a Dictionary?ChallengeDictionary MethodsChallenge
5. Loops
while LoopChallengefor LoopChallengeRangeChallengeIterating Over IndexesNested Loops
6. Functions
Built-in FunctionsChallengeDefining Your First FunctionChallengeif/else Statements in FunctionsChallengeFunctions With No ReturnChallengeModifying FunctionsChallengeLambda FunctionsChallenge

bookList Methods

Let's explore some basic techniques to work with lists:

  • len(t) - returns the length of list t, or in other words, the number of items it contains;
  • list1 + list2 - combines two lists (both must be lists);
  • t * n - creates n duplicates of list t;
  • t.append(x) - adds a single item x to the end of list t (this alters the original list);
  • t.extend([x, y, ...]) - appends elements x, y, ... to the end of list t (this also modifies the original list);
  • t.copy() - produces a duplicate of the list t;
  • t.count(x) - tallies the number of occurrences of x in list t.

As an example, let's enhance the list from our last discussion by adding more details, such as the capital city and the total number of states:


              
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# Initial and new lists
US_Info = ["USA", 9629091, 331002651]
US_Info_new = ["Washington D.C.", 50]

# Add new data using concatenation
print(US_Info + US_Info_new)

# Add new data using list method
US_Info.extend(US_Info_new)
print(US_Info)
copy

Note

Keep in mind that the .extend() method needs an iterable object as its argument. In our case, we're using another list as the iterable.

An iterable object in Python is an object that can be iterated over, meaning you can traverse through all its elements in a sequence, such as a list, tuple, or string.

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Section 4. Chapter 2
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