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+--- Thread: How does "Run Time" in Python make sense? (/thread-40985.html)
How does "Run Time" in Python make sense? - stamp1t - Oct-25-2023
Hello, I don't understand why it makes sense to talk about "runtime" in Python. In Python, each line is read, interpreted, and executed one by one. So depending on how you look at it, there is either "only" runtime because there are no other phases, or there is no runtime "phase" at all because it is always immediately interrupted by the reading and interpretation phases. So, how can a runtime error, for example, occur?
RE: How does "Run Time" in Python make sense? - snippsat - Oct-26-2023
So under is the step that Python code go trough,then is easier to talk about what happens.
When we talk about
runtime errors in Python,we are referring to the phase where the Python interpreter is actively executing the code.A runtime error is an error that occurs while the program is running,
as opposed to a
syntax error or other type of error that might be caught earlier in the process.In other words, a
runtime error is an error that occurs after the Python interpreter has successfully parsed and understood the code,but encounters an issue while trying to execute it.
For example, consider the following Python code:
x = 1 / 0This code will cause a runtime error
ZeroDivisionError because the Python interpreter is able to understand and parse the code,but it cannot execute the division operation because division by zero is not defined.
The error occurs
at runtime, when the interpreter attempts to execute the division operation,rather than at the time the code is written or parsed.AI Friend Wrote:Python's process for executing code can be broadly summarized in the following steps:
Source Code: The program is written as a set of instructions in a file with the .py extension.
This is known as the source code.
It's important to note that while Python is often referred to as an interpreted language,
- Lexical Analysis: The Python interpreter reads the source code and converts it into a stream of tokens using a process known as lexical analysis or tokenization.
A token is a meaningful unit in the program, such as a keyword, operator, or identifier.
- Parsing: The stream of tokens is then parsed into a data structure known as the abstract syntax tree (AST).
The AST represents the syntactic structure of the program and helps the interpreter to understand the relationships between different parts of the code.
- Compilation: The AST is then compiled into bytecode. Bytecode is a lower-level, platform-independent representation of the source code.
In Python, bytecode is stored in .pyc files in the __pycache__ directory.
- Execution: Finally, the bytecode is executed by the Python Virtual Machine (PVM).
The PVM is a part of the Python runtime system that interprets the bytecode and carries out the instructions in the program.
This is the phase where the program actually runs and produces output or performs actions.
it actually follows a process that involves both compilation and interpretation.
The compilation step converts the source code into bytecode,
and the interpretation step executes the bytecode to run the program.