For a given 'node' and 'attr' print API properties and it's "attributeAffects" for the attribute - for inspecting/debugging attributes from existing nodes.

maya_query_attribute_api_properties_and_affects.py

import maya.api.OpenMaya as om

node = "myNode"
attr = "myAttribute"

sel = om.MSelectionList()
sel.add(node)
fn_dep = om.MFnDependencyNode(sel.getDependNode(0))
o_attr = fn_dep.attribute(attr)
fn_attr = om.MFnAttribute(o_attr)

print '-- properties'
for property in [
    "affectsAppearance",
    "affectsWorldSpace",
    "array",
    "cached",
    "channelBox",
    "connectable",
    "disconnectBehavior",
    "dynamic",
    "extension",
    "hidden",
    "indeterminant",
    "indexMatters",
    "internal",
    "isProxyAttribute",
    "keyable",
    "name",
    "parent",
    "readable",
    "renderSource",
    "shortName",
    "storable",
    "usedAsColor",
    "usedAsFilename",
    "usesArrayDataBuilder",
    "worldSpace",
    "writable"
]:
    print property, getattr(fn_attr, property)

print '-- getAddAttrCmd'
print fn_attr.getAddAttrCmd(True)

print '-- getAffectedAttributes'
for dep_attr in fn_dep.getAffectedAttributes(o_attr):
    print om.MFnAttribute(dep_attr).name

print '-- getAffectingAttributes'
for dep_attr in fn_dep.getAffectingAttributes(o_attr):
    print om.MFnAttribute(dep_attr).name