五段代码的完整判定

把这条路线用的五段代码，一次性判完：

import ast, io, tokenize

LEX = 'x = (1 + 2'
SYN = 'if x > 1\n    y = 2'
SEM = 'return 1'
RUN = 'y = undefined_name'
OK  = 'y = 1 + 1'

def stage_of(src):
    try:
        list(tokenize.generate_tokens(io.StringIO(src).readline))
    except (tokenize.TokenError, IndentationError, SyntaxError):
        return "词法"
    try:
        ast.parse(src)
    except SyntaxError:
        return "语法"
    try:
        code = compile(src, "<s>", "exec")
    except SyntaxError:
        return "语义"
    try:
        exec(code, {})
    except NameError:
        return "运行"
    return "通过"

print("/".join(stage_of(s) for s in (LEX, SYN, SEM, RUN, OK)))