eric6/Plugins/CheckerPlugins/CodeStyleChecker/AstUtilities.py

Thu, 08 Apr 2021 18:27:47 +0200

author
Detlev Offenbach <detlev@die-offenbachs.de>
date
Thu, 08 Apr 2021 18:27:47 +0200
changeset 8205
4a0f1f896341
parent 7923
91e843545d9a
permissions
-rw-r--r--

Applied some code simplifications suggested by the new Simplify checker.

```# -*- coding: utf-8 -*-

# Copyright (c) 2019 - 2021 Detlev Offenbach <detlev@die-offenbachs.de>
#

"""
Module implementing some utility and compatibility functions for working with
the ast module.
"""

import sys
import ast

if sys.version_info >= (3, 8, 0):
# functions for Python >= 3.8

import numbers

def isNumber(node):
"""
Function to check that a node is a number.

@param node reference to the node to check
@type ast.AST
@return flag indicating a number
@rtype bool
"""
return (
isinstance(node, ast.Constant) and
isinstance(node.value, numbers.Number)
)

def isString(node):
"""
Function to check that a node is a string.

@param node reference to the node to check
@type ast.AST
@return flag indicating a string
@rtype bool
"""
return (
isinstance(node, ast.Constant) and
isinstance(node.value, str)
)

def isBytes(node):
"""
Function to check that a node is a bytes.

@param node reference to the node to check
@type ast.AST
@return flag indicating a bytes
@rtype bool
"""
return (
isinstance(node, ast.Constant) and
isinstance(node.value, bytes)
)

def isBaseString(node):
"""
Function to check that a node is a bytes or string.

@param node reference to the node to check
@type ast.AST
@return flag indicating a bytes or string
@rtype bool
"""
return (
isinstance(node, ast.Constant) and
isinstance(node.value, (bytes, str))
)

def isNameConstant(node):
"""
Function to check that a node is a name constant.

@param node reference to the node to check
@type ast.AST
@return flag indicating a name constant
@rtype bool
"""
return (
isinstance(node, ast.Constant) and
not isinstance(node.value, (bytes, str, numbers.Number))
)

def getValue(node):
"""
Function to extract the value of a node.

@param node reference to the node to extract the value from
@type ast.Constant
@return value of the node
@rtype any
@exception TypeError raised to indicate an unsupported type
"""
if not isinstance(node, ast.Constant):
raise TypeError("Illegal node type passed.")

return node.value

else:
# functions for Python < 3.8

def isNumber(node):
"""
Function to check that a node is a number.

@param node reference to the node to check
@type ast.AST
@return flag indicating a number
@rtype bool
"""
return isinstance(node, ast.Num)

def isString(node):
"""
Function to check that a node is a string.

@param node reference to the node to check
@type ast.AST
@return flag indicating a string
@rtype bool
"""
return isinstance(node, ast.Str)

def isBytes(node):
"""
Function to check that a node is a bytes.

@param node reference to the node to check
@type ast.AST
@return flag indicating a bytes
@rtype bool
"""
return isinstance(node, ast.Bytes)

def isBaseString(node):
"""
Function to check that a node is a bytes or string.

@param node reference to the node to check
@type ast.AST
@return flag indicating a bytes or string
@rtype bool
"""
return isinstance(node, (ast.Str, ast.Bytes))

def isNameConstant(node):
"""
Function to check that a node is a name constant.

@param node reference to the node to check
@type ast.AST
@return flag indicating a name constant
@rtype bool
"""
return isinstance(node, ast.NameConstant)

def getValue(node):
"""
Function to extract the value of a node.

@param node reference to the node to extract the value from
@type one of ast.Num, ast.Str, ast.Bytes or ast.NameConstant
@return value of the node
@rtype one of str, bytes, int
@exception TypeError raised to indicate an unsupported type
"""
if not isinstance(
node, (ast.Num, ast.Str, ast.Bytes, ast.NameConstant)
):
raise TypeError("Illegal node type passed.")

if isinstance(node, ast.Num):
return node.n

elif isinstance(node, (ast.Str, ast.Bytes)):
return node.s

elif isinstance(node, ast.NameConstant):
return node.value

return None```