Intro to Python
Words and Sentences in Python
Python Reserved Words:
Python has a small set of reserved words that hold special meanings (e.g.,
if,else,for), which cannot be used as variable names.Example of valid syntax:
print('Hello world!').
Conversing with Python
Engaging with Python:
Python operates in an interactive mode where you can execute commands directly (prompted by
>>>).Errors in syntax (e.g.,
primt 'Hello world!') indicate issues needing correction.Proper exit command is
quit().
Terminology: Interpreter and Compiler
High-Level vs Low-Level Languages:
High-level languages (e.g., Python) are designed for human ease of use, while low-level languages (e.g., machine code) are suited for direct CPU execution.
Interpreters and Compilers:
Interpreter: Processes code line-by-line, making it easier to test and debug interactively.
Compiler: Translates the entire program into machine code for execution in a non-interactive mode.
Writing a Program
Script Development:
Python programs are commonly written in text files (scripts), which are conventionally named with a
.pyextension.Example shell command:
python hello.pyexecutes a script namedhello.py.
Building Blocks of Programs
Basic Constructs:
Input/Output, Sequential Execution, Conditional Execution, Repeated Execution, Reuse:
Programs utilize these constructs to process data and produce results.
Debugging and Error Types
Types of Errors:
Syntax Errors: Incorrect grammar in code; easiest to fix.
Logic Errors: Correct syntax but incorrect program flow; often requires a deeper understanding of program logic.
Semantic Errors: Code that runs without errors but produces unexpected results; a misunderstanding of functionality.
The Learning Journey
Conceptual Progression:
Learning programming is similar to acquiring a language; it develops over time and requires practice.
Strategies for overcoming challenges include stepping back, taking breaks, and engaging with peers for discussions.