ast practice 1

ast_practice_1.py

import ast

source = """
name = "Inu"
age = 10
print("Hello, {}({})!".format(name, age))
"""

tree = ast.parse(source)

def print_ast(node, level=0, prefixes="", is_last=True):
    
    if level >= 1:
        prefix = " `-- " if is_last else " |-- "
    else:
        prefix = ""
    
    class_name = node.__class__.__name__
    fields = []
    for n, v in ast.iter_fields(node):
        if isinstance(v, str):
            fields.append('{}="{}"'.format(n, v))
        elif isinstance(v, int):
            fields.append("{}={}".format(n, v))
        else:
            fields.append("{}".format(n))
    
    field_string = ", ".join(fields)
    
    print("{}{}{} ({})".format(prefixes, prefix, class_name, field_string))
    
    children = tuple(ast.iter_child_nodes(node))
    l = len(children)
    
    if level >= 1:
        prefixes += "     " if is_last else " |   "
    
    for i, n in enumerate(children):
        print_ast(n, level + 1, prefixes, i + 1 == l)

print_ast(tree)
"""==>
Module (body, docstring)
 |-- Assign (targets, value)
 |    |-- Name (id="name", ctx)
 |    |    `-- Store ()
 |    `-- Str (s="Inu")
 |-- Assign (targets, value)
 |    |-- Name (id="age", ctx)
 |    |    `-- Store ()
 |    `-- Num (n=10)
 `-- Expr (value)
      `-- Call (func, args, keywords)
           |-- Name (id="print", ctx)
           |    `-- Load ()
           `-- Call (func, args, keywords)
                |-- Attribute (value, attr="format", ctx)
                |    |-- Str (s="Hello, {}({})!")
                |    `-- Load ()
                |-- Name (id="name", ctx)
                |    `-- Load ()
                `-- Name (id="age", ctx)
                     `-- Load ()
"""