我们从Python开源项目中，提取了以下17个代码示例，用于说明如何使用ast.Assert()。
def __init__(self, stmt, context): self.stmt = stmt self.context = context self.stmt_table = { ast.Expr: self.expr, ast.Pass: self.parse_pass, ast.AnnAssign: self.ann_assign, ast.Assign: self.assign, ast.If: self.parse_if, ast.Call: self.call, ast.Assert: self.parse_assert, ast.For: self.parse_for, ast.AugAssign: self.aug_assign, ast.Break: self.parse_break, ast.Return: self.parse_return, } stmt_type = self.stmt.__class__ if stmt_type in self.stmt_table: self.lll_node = self.stmt_table[stmt_type]() elif isinstance(stmt, ast.Name) and stmt.id == "throw": self.lll_node = LLLnode.from_list(['assert', 0], typ=None, pos=getpos(stmt)) else: raise StructureException("Unsupported statement type", stmt)
def get_coverable_nodes(cls): return { ast.Assert, ast.Assign, ast.AugAssign, ast.Break, ast.Continue, ast.Delete, ast.Expr, ast.Global, ast.Import, ast.ImportFrom, ast.Nonlocal, ast.Pass, ast.Raise, ast.Return, ast.FunctionDef, ast.ClassDef, ast.TryExcept, ast.TryFinally, ast.ExceptHandler, ast.If, ast.For, ast.While, }
def get_coverable_nodes(cls): return { ast.Assert, ast.Assign, ast.AugAssign, ast.Break, ast.Continue, ast.Delete, ast.Expr, ast.Global, ast.Import, ast.ImportFrom, ast.Nonlocal, ast.Pass, ast.Raise, ast.Return, ast.ClassDef, ast.FunctionDef, ast.Try, ast.ExceptHandler, ast.If, ast.For, ast.While, }
def isStatement(a): """Determine whether the given node is a statement (vs an expression)""" return type(a) in [ ast.Module, ast.Interactive, ast.Expression, ast.Suite, ast.FunctionDef, ast.ClassDef, ast.Return, ast.Delete, ast.Assign, ast.AugAssign, ast.For, ast.While, ast.If, ast.With, ast.Raise, ast.Try, ast.Assert, ast.Import, ast.ImportFrom, ast.Global, ast.Expr, ast.Pass, ast.Break, ast.Continue ]
def test_assert(self): self.stmt(ast.Assert(ast.Name("x", ast.Store()), None), "must have Load context") assrt = ast.Assert(ast.Name("x", ast.Load()), ast.Name("y", ast.Store())) self.stmt(assrt, "must have Load context")
def run(self, mod): """Find all assert statements in *mod* and rewrite them.""" if not mod.body: # Nothing to do. return # Insert some special imports at the top of the module but after any # docstrings and __future__ imports. aliases = [ast.alias(py.builtin.builtins.__name__, "@py_builtins"), ast.alias("_pytest.assertion.rewrite", "@pytest_ar")] expect_docstring = True pos = 0 lineno = 0 for item in mod.body: if (expect_docstring and isinstance(item, ast.Expr) and isinstance(item.value, ast.Str)): doc = item.value.s if "PYTEST_DONT_REWRITE" in doc: # The module has disabled assertion rewriting. return lineno += len(doc) - 1 expect_docstring = False elif (not isinstance(item, ast.ImportFrom) or item.level > 0 or item.module != "__future__"): lineno = item.lineno break pos += 1 imports = [ast.Import([alias], lineno=lineno, col_offset=0) for alias in aliases] mod.body[pos:pos] = imports # Collect asserts. nodes = [mod] while nodes: node = nodes.pop() for name, field in ast.iter_fields(node): if isinstance(field, list): new = [] for i, child in enumerate(field): if isinstance(child, ast.Assert): # Transform assert. new.extend(self.visit(child)) else: new.append(child) if isinstance(child, ast.AST): nodes.append(child) setattr(node, name, new) elif (isinstance(field, ast.AST) and # Don't recurse into expressions as they can't contain # asserts. not isinstance(field, ast.expr)): nodes.append(field)
def visit_Assert(self, assert_): """Return the AST statements to replace the ast.Assert instance. This re-writes the test of an assertion to provide intermediate values and replace it with an if statement which raises an assertion error with a detailed explanation in case the expression is false. """ if isinstance(assert_.test, ast.Tuple) and self.config is not None: fslocation = (self.module_path, assert_.lineno) self.config.warn('R1', 'assertion is always true, perhaps ' 'remove parentheses?', fslocation=fslocation) self.statements = [] self.variables = [] self.variable_counter = itertools.count() self.stack = [] self.on_failure = [] self.push_format_context() # Rewrite assert into a bunch of statements. top_condition, explanation = self.visit(assert_.test) # Create failure message. body = self.on_failure negation = ast.UnaryOp(ast.Not(), top_condition) self.statements.append(ast.If(negation, body, [])) if assert_.msg: assertmsg = self.helper('format_assertmsg', assert_.msg) explanation = "\n>assert " + explanation else: assertmsg = ast.Str("") explanation = "assert " + explanation template = ast.BinOp(assertmsg, ast.Add(), ast.Str(explanation)) msg = self.pop_format_context(template) fmt = self.helper("format_explanation", msg) err_name = ast.Name("AssertionError", ast.Load()) exc = ast_Call(err_name, [fmt], []) if sys.version_info[0] >= 3: raise_ = ast.Raise(exc, None) else: raise_ = ast.Raise(exc, None, None) body.append(raise_) # Clear temporary variables by setting them to None. if self.variables: variables = [ast.Name(name, ast.Store()) for name in self.variables] clear = ast.Assign(variables, _NameConstant(None)) self.statements.append(clear) # Fix line numbers. for stmt in self.statements: set_location(stmt, assert_.lineno, assert_.col_offset) return self.statements
def visit_Assert(self, assert_): """Return the AST statements to replace the ast.Assert instance. This re-writes the test of an assertion to provide intermediate values and replace it with an if statement which raises an assertion error with a detailed explanation in case the expression is false. """ self.statements = [] self.variables = [] self.variable_counter = itertools.count() self.stack = [] self.on_failure = [] self.push_format_context() # Rewrite assert into a bunch of statements. top_condition, explanation = self.visit(assert_.test) # Create failure message. body = self.on_failure negation = ast.UnaryOp(ast.Not(), top_condition) self.statements.append(ast.If(negation, body, [])) if assert_.msg: assertmsg = self.helper('format_assertmsg', assert_.msg) explanation = "\n>assert " + explanation else: assertmsg = ast.Str("") explanation = "assert " + explanation template = ast.BinOp(assertmsg, ast.Add(), ast.Str(explanation)) msg = self.pop_format_context(template) fmt = self.helper("format_explanation", msg) err_name = ast.Name("AssertionError", ast.Load()) exc = ast_Call(err_name, [fmt], []) if sys.version_info[0] >= 3: raise_ = ast.Raise(exc, None) else: raise_ = ast.Raise(exc, None, None) body.append(raise_) # Clear temporary variables by setting them to None. if self.variables: variables = [ast.Name(name, ast.Store()) for name in self.variables] clear = ast.Assign(variables, _NameConstant(None)) self.statements.append(clear) # Fix line numbers. for stmt in self.statements: set_location(stmt, assert_.lineno, assert_.col_offset) return self.statements
