bytecode

Dynamic typing (part 1)

lpoulain bytecode, Python
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Python is a dynamically-typed language, just like PHP, JavaScript or Ruby, and contrary to statically-typed languages such as C/C++, Java or Scala.

In a dynamically-typed language, the code can never know in advance what will be the type of any variable. You can define a function to perform a particular operation on, say, a collection, but unless you explicitly filter out an argument that is not a collection, the code is never certain that it is indeed one – and the bytecode compiler sure cannot be certain either.

Using dynamic types has consequences for the language – both from a conceptual standpoint and from an implementation standpoint.
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Python bytecode

lpoulain bytecode

Just like Java or C#, CPython is compiling the code into bytecode which is then interpreted by a virtual machine. The Python library dis allows to disassemble Python code and to see how are things are compiled under the hood. Consider the following code:

>>> def test():
...     for i in range(10):
...             print(i)
...

You can call dis.dis(test) to display the compiled bytecode, and dis.show_code(test) to understand the symbols referenced by that bytecode. Continue reading →