Course Content
Introduction to Python
Introduction to Python
2. Variables and Types in Python
How to Store Numbers in PythonPython Naming Rules for VariablesHow to Work with Variables in PythonData Types in PythonChallenge: Converting Kilometers to MilesStore Text with Strings in PythonString Indexing in PythonNegative Indexing and String Length in PythonString Slicing in PythonChallenge: Retrieving Letters from StringString Concatenation in Python
3. Conditional Statements in Python
Boolean Data Type in PythonChallenge: Working with Comparison OperatorsHow to Combine Conditions in PythonChallenge: Working with Logical OperatorsMembership Operators and Type Comparisons in PythonHow to Use if/else Expressions in PythonChallenge: Running a Grocery StoreChallenge: Creating Odd and Even Logicif/elif/else ExpressionsChallenge: Running Grocery Store ExtendedChallenge: Weather Adviser
4. Other Data Types in Python
Python ListsCommon List Methods in PythonChallenge: Updating ListNested Lists in PythonChallenge: Retrieving Information from Nested ListPython TuplesCommon Tuple Methods in PythonChallenge: Updating TupleNested Tuples in PythonChallenge: Retrieving Information from Nested TuplePython DictionariesChallenge: Creating DictionaryCommon Dictionary Methods in PythonChallenge: Updating Dictionary
6. Functions in Python
Built-in Functions in PythonChallenge: Converting HeightsHow to Create Functions in PythonsChallenge: Writing First FunctionUse of if/else Statements in Python FunctionsChallenge: Identifying Positive Values Functions Without Return in PythonChallenge: Creating Logging FunctionModifying Functions in PythonChallenge: Updating Logic of the FunctionLambda Functions in PythonChallenge: Creating Lambda Function
Common Dictionary Methods in Python
Dictionaries have unique characteristics that set them apart from lists and tuples. They also come with their own set of methods.
len(d)
- returns the number ofkey:value
pairs in the dictionaryd
;d.copy()
- creates a copy of the dictionaryd
;d.items()
- provides all thekey, value
pairs from the dictionaryd
;d.keys()
- lists all the keys in the dictionaryd
;d.values()
- provides all the values from the dictionaryd
.
Unlike lists, dictionaries don't use methods like .append()
or .extend()
, nor do they support concatenation like strings. Instead, since dictionaries store data as key-value pairs, you add new entries by simply assigning a value to a key.
d[k] = e
– assigns the valuee
to the keyk
. Ifk
already exists in the dictionary, its value is updated otherwise, a new key-value pair is added.
# Initial dictionary countries_dict = {'USA': (9629091, 331002651), 'Canada': (9984670, 37742154), 'Germany': (357114, 83783942)} # Update dictionary with two countries countries_dict["Brazil"] = (8515767, 212559417) countries_dict["India"] = (3166391, 1380004385) # Printing dictionary print(countries_dict)
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Section 4. Chapter 13