Sylvain Thénault on ASTroid


December 11th, 2015

47 mins 28 secs

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About this Episode

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The Python AST (Abstract Syntax Tree) is a powerful abstraction that allows for a number of innovative projects. ASTroid is a library that provides additional convenience methods to simplify working with the AST. In this episode we spoke with Sylvain Thénault from Logilab about his work on ASTroid and how it is used to power the popular PyLint static analysis tool.

Brief Introduction

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  • We are recording today on November 23rd, 2015 and your hosts as usual are Tobias Macey and Chris Patti
  • Today we are interviewing Sylvain Thénault about ASTroid
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Interview with Sylvain Thénault

  • Introductions
  • How did you get introduced to Python? – Chris
  • Can you explain what an Abstract Syntax Tree is and why it is a useful language feature? – Tobias
  • What was your inspiration for creating ASTroid? – Chris
  • What features does ASTroid offer over Python’s standard AST package, and what makes those features important? – Chris
  • I know that the ASTroid package is used in Pylint which is also maintained by Logilab. How does the AST facilitate static analysis of Python projects and are there cases where you have to fall back to text parsing? – Tobias
  • Beyond static analysis, what are some of the other possible uses for the Python AST? – Tobias
  • The documentation for the AST package in Python mentions that the specific syntax objects in the tree are subject to change between releases. Does the ASTroid package provide any abstractions to maintain a consistent API between versions or does it just provide a pass-through? – Tobias
  • Have you encountered any challenges in testing ASTroid given that it operates at such a low level in the language? – Chris
  • Do you have trouble attracting contributors given the great understanding of Python’s inner working required? – Chris
  • Does the implementation or representation of the AST differ between different distributions of Python such as CPython, PyPy and Jython? – Tobias
  • What are some of the most interesting applications ASTroid has been used in? – Chris


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The intro and outro music is from Requiem for a Fish The Freak Fandango Orchestra / CC BY-SA