ast-tools 0.0.14

Toolbox for working with the Python AST

Toolbox for working with the Python AST

pip install ast_tools

Useful References

• Green Tree Snakes - the missing Python AST docs

Macros

Loop Unrolling

Unroll loops using the pattern

for <var> in ast_tools.macros.unroll(<iter>):
    ...

<iter> should be an iterable object that produces integers (e.g. range(8)) that can be evaluated at definition time (can refer to variables in the scope of the function definition)

For example,

from ast_tools.passes import begin_rewrite, loop_unroll, end_rewrite

@end_rewrite()
@loop_unroll()
@begin_rewrite()
def foo():
    for i in ast_tools.macros.unroll(range(8)):
        print(i)

is rewritten into

def foo():
    print(0)
    print(1)
    print(2)
    print(3)
    print(4)
    print(5)
    print(6)
    print(7)

You can also use a list of ints, here's an example that also uses a reference to a variable defined in the outer scope:

from ast_tools.passes import begin_rewrite, loop_unroll, end_rewrite

j = [1, 2, 3]
@end_rewrite()
@loop_unroll()
@begin_rewrite()
def foo():
    for i in ast_tools.macros.unroll(j):
        print(i)

becomes

def foo():
    print(1)
    print(2)
    print(3)