Get Started with Python - Part 1
This is the first part of the Jump In guide introducing core Python concepts in a hands-on way. This page will cover datatypes and operators, including interactive code. Be sure to check out the accompanying notebook for more hands-on experience.
Use the Run Code button to execute code live. Make edits and compare the output to figure out how Python works. If anything goes wrong, just reload the page to reset all code. And remember cell edits are not saved. Check out the notebook options, where you can download and save edits if you want to keep a record of your work.
My First Code
Time to get started! The cell below will output the text when run. Be sure to pay attention to the syntax-the organization and structure-used.
Update the string with a custom response like ‘Hello, World!’ or ‘Let’s dive in!’. Be sure to Run the cell after each update.
The above cell uses the Python print function (more on functions in the next lesson) to output a string that is passed to it. A string is a datatype in Python that represents text. Basic Python datatypes are presented next.
Datatypes
Python uses datatypes to organize and process information. The datatype can determine how information is stored, used, and displayed. Picking the right datatype makes coding much smoother. Key categories include numeric, strings, and sequences.
Key concepts of datatypes include:
-Item or Sequence/Collection: Datatypes like the numeric int and float represent an item while sequences and colletions can include multiple elements
-Ordered: Datatypes like lists and tuples keep items in order whereas dictionaries are unordered
-Mutable: Mutable datatypes including lists can changed after being defined whereas immutable datatypes like tuples can not
-Mappings: Dicionaries store data as key-value pairs
See Iteration and Flow Control for more on working with sequences and Boolean types often used for flow control.
| Category | Type | Definition | Example |
|---|---|---|---|
| Numbers | int | Whole number with no decimal or fraction | 42 |
| Numbers | float | Real number with decimal or fraction | 3.14 |
| Text | str | A sequence of characters | “hello” |
| Sequences | list | Ordered, mutable collection of items | [1, 2, 3] |
| Sequences | tuple | Ordered, immutable collection of items | (1, 2, 3) |
| Mappings | dict | Unordered, mutable collection of key-value pairs | {“a”: 1, “b”: 2} |
| Boolean | bool | True or False value | True, False |
| Special | NoneType | Represents undefined or null value | None |
Datatypes in Code
The type function is used to verify types. Experiment by copying any of the examples into the below to replace the list. Note: Quotes are used to indicated text, so "hello" is valid but hello is not.
Python determines type based on syntax if not explicitly stated. This cell shows how set a number can be set as an integer or a string.
Operators
Operations in programming are used to manipulate and evaluate values. These allow programs to perform calculations, make decisions, and control the flow of execution.
Types include:
- Mathematical
- Logical
- Comparison
- Assignment
Mathematical
Mathematical operators perform arithmetic calculations. In Python, these include + (addition), - (subtraction), * (multiplication), and / (division). Python uses // for integer division. Regular division will return a float value, while integer division will discard the remainder and return an integer.
Not shown here, but available are also ** or ^ (exponentiation), and % or %% (modulus).
| Operator | Example | Meaning | Result |
|---|---|---|---|
| + | 3 + 2 | Addition | 5 |
| - | 7 - 4 | Subtraction | 3 |
| * | 6 * 2 | Multiplication | 12 |
| / | 7 / 2 | Division (always float) | 3.5 |
| // | 7 // 2 | Floor (integer) division | 3 |
Use the cell below to run a addition example. Experiment with other operators and values.
Comparison
Comparison operators evaluate relationships between values. Common operators in Python include == (equal), != (not equal), < (less than), <= (less than or equal to), > (greater than), and >= (greater than or equal to).
These return boolean values of True/False.
| Operator | Example | Meaning | Result |
|---|---|---|---|
| == | 3 == 3 | Equal to | True |
| != | 3 != 4 | Not equal to | True |
| > | 5 > 2 | Greater than | True |
| < | 2 < 5 | Less than | True |
| >= | 5 >= 5 | Greater than or equal to | True |
| <= | 4 <= 5 | Less than or equal to | True |
Logical
Logical operators allow for boolean logic. In Python: and, or, not. These are used in conditionals and loops to combine multiple logical expressions.
| Operator | Example | Meaning | Result |
|---|---|---|---|
| and | (3 > 1) and (2 < 5) | True if both are true | True |
| or | (3 > 1) or (2 > 5) | True if at least one is true | True |
| not | not (3 > 1) | Negates (True → False) | False |
Assignment
Assignment uses = to assign a value to a variable. x = 10 creates or updates the variable x to be 10.
Equality checking uses == and returns a Boolean (True, or False) depending on if the values are equal. x == 10 will return True if x is set as above.
Next Steps
Explore these concepts more with an interactive notebook or keep learning with variables and functions next.