Explanation of Compilers, Interpreters and Bytecode using a number of sources - related to Python programming.

1. S
CSC 121 Programming 1
Compilers, Interpreters
and Bytecode

2. What is a Compiler
 A program that translates
(or compiles) a high-level
language into a low-level
language.

3. What is a
Low-Level Language?
 A low-level language is lower (or
closer) to the CPU and hardware;
 Uses primitive instructions
(binary code) that a machine can
understand, but is more difficult for
humans to read or write.

4. Low-Level Language
 Examples are Machine code
(closest to hardware – binary code)
 Assembly Language – slightly less
cryptic.

5. High-Level Language
 A high-level language uses language
that humans can read, understand and
write more easily. Code is compose in a
text/code editor or IDE.

6. High-Level Language
 Examples of popular high-level
programming languages today are:
C, C++, Java, & Python
 FORTRAN was first
high-level language.

7. Compiling High-Level Source
Code into Machine Code
 High-level language source code,
written by programmers (using C
or C++) needs to be compiled into
executable machine code.
 A compiler program will translate the
source code into executable binary
code (all at one time).

8. Compiling High-Level Source
Code into Machine Code
 Programs which need to use a lot of
computer resources, and need to be as
efficient as possible, are often written
in a compiled language like C.
 C in many ways is a lower-level than
Python. For example, a C programmer
needs to handle a lot more memory
management than a Python programmer.

9. Compiling High-Level Source
Code into Machine Code
 Compiled code is fast and efficient
 But is platform dependent –
meaning it must be compiled
for a particular Operating System
or CPU.

10. Interpreted
High-Level Source Code
 Languages like Java and Python are
interpreted line by line by an
interpreter before being translated
into code that the CPU can use.
 This takes longer (is slower), but
allows the language to run on
multiple Operating Systems.

11. Interpreted Languages
 Java and Python source code are
first compiled (translated) into
bytecode which is then executed by
a virtual machine – Java Virtual
Machine or Python Virtual Machine.
 Virtual means it emulates the CPU
or hardware in a sense.

12. Interpreted Languages
- Python -
Python Interpreter

13. Inside the
Python Interpreter
Sometimes
referred to as
translator
hello-cpython-36.pyc
hello.py Operating
System

14. Interpreted Languages - Java

15. Sources:
 Python Concepts - What is a Python Compiler and
Python Virtual Machine?
(Moondra YouTube Channel)
 Inside Python: What is bytecode and pyc files?
(Indian Pythonista YouTube Channel)
 https://python-textbok.readthedocs.io/