transformations.py 文件源码

def listNotEmpty(a):
    """Determines that the iterable is NOT empty, if we can know that"""
    """Used for For objects"""
    if not isinstance(a, ast.AST):
        return False
    if type(a) == ast.Call:
        if type(a.func) == ast.Name and a.func.id in ["range"]:
            if len(a.args) == 1: # range(x)
                return type(a.args[0]) == ast.Num and type(a.args[0].n) != complex and a.args[0].n > 0
            elif len(a.args) == 2: # range(start, x)
                if type(a.args[0]) == ast.Num and type(a.args[1]) == ast.Num and \
                    type(a.args[0].n) != complex and type(a.args[1].n) != complex and \
                    a.args[0].n < a.args[1].n:
                    return True
                elif type(a.args[1]) == ast.BinOp and type(a.args[1].op) == ast.Add:
                    if type(a.args[1].right) == ast.Num and type(a.args[1].right) != complex and a.args[1].right.n > 0 and \
                        compareASTs(a.args[0], a.args[1].left, checkEquality=True) == 0:
                        return True
                    elif type(a.args[1].left) == ast.Num and type(a.args[1].left) != complex and a.args[1].left.n > 0 and \
                        compareASTs(a.args[0], a.args[1].right, checkEquality=True) == 0:
                        return True
    elif type(a) in [ast.List, ast.Tuple]:
        return len(a.elts) > 0
    elif type(a) == ast.Str:
        return len(a.s) > 0
    return False