def py2melProc( function, returnType=None, procName=None, evaluateInputs=True, argTypes=None ):
"""This is a work in progress. It generates and sources a mel procedure which wraps the passed
python function. Theoretically useful for calling your python scripts in scenarios where Maya
does not yet support python callbacks.
The function is inspected in order to generate a MEL procedure which relays its
arguments on to the python function. However, Python features a very versatile argument structure whereas
MEL does not.
- python args with default values (keyword args) will be set to their MEL analogue, if it exists.
- normal python args without default values default to strings. If 'evaluteInputs' is True, string arguments passed to the
MEL wrapper proc will be evaluated as python code before being passed to your wrapped python
function. This allows you to include a typecast in the string representing your arg::
myWrapperProc( "Transform('persp')" );
- *args : not yet implemented
- **kwargs : not likely to be implemented
function
This can be a callable python object or the full, dotted path to the callable object as a string.
If passed as a python object, the object's __name__ and __module__ attribute must point to a valid module
where __name__ can be found.
If a string representing the python object is passed, it should include all packages and sub-modules, along
with the function's name: 'path.to.myFunc'
procName
Optional name of the mel procedure to be created. If None, the name of the function will be used.
evaluateInputs
If True (default), string arguments passed to the generated mel procedure will be evaluated as python code, allowing
you to pass a more complex python objects as an argument. For example:
In python:
>>> import pymel.tools.py2mel as py2mel
>>> def myFunc( arg ):
... for x in arg:
... print x
>>> py2mel.py2melProc( myFunc, procName='myFuncWrapper', evaluateInputs=True )
Then, in mel::
// execute the mel-to-python wrapper procedure
myFuncWrapper("[ 1, 2, 3]");
the string "[1,2,3]" will be converted to a python list [1,2,3] before it is executed by the python function myFunc
"""
function = _getFunction( function )
funcName = function.__name__
melCompile = []
melArgs = []
melArrayToStrDecls = []
argList, defaults, description = getMelArgs(function)
if argTypes:
if isMapping(argTypes):
pass
elif isIterable(argTypes):
tmp = argTypes
argTypes = {}
for i, argType in enumerate(tmp):
argTypes[argList[i][0]] = argType
else:
raise ValueError, "argTypes must be iterable or mapping type"
for argType in argTypes.values():
if not isValidMelType(argType):
raise TypeError, "%r is not a valid mel type: %s" % (argType, ', '.join(MELTYPES))
else:
argTypes = {}
for arg, melType in argList:
if melType == 'string':
compilePart = "'\" + $%s + \"'" % arg
melCompile.append( compilePart )
elif melType == None:
melType = 'string'
compilePart = "'\" + $%s + \"'" % arg
compilePart = r'eval(\"\"\"%s\"\"\")' % compilePart
melCompile.append( compilePart )
elif melType.count('[]'):
melArrayToStrDecls.append( 'string $_%s ="("; int $i=0;for($i; $i<size($%s); $i++) { $_%s += ($%s[$i] + ","); } $_%s += ")";' % (arg, arg, arg, arg, arg))
melCompile.append( "'\" + $_%s + \"'" % arg )
else:
melCompile.append( "\" + $%s + \"" % arg )
if melType.count('[]'):
melType = melType.replace('[]','')
melArgs.append( '%s $%s[]' % (melType, arg) )
else:
melArgs.append( '%s $%s' % (melType, arg) )
if procName is None:
procName = funcName
procDef = """global proc %s %s( %s ){ %s
python("import %s; %s._functionStore[%r](%s)");}""" % ( returnType if returnType else '',
procName,
', '.join(melArgs),
''.join(melArrayToStrDecls),
__name__,
__name__,
repr(function),
','.join(melCompile) )
_functionStore[repr(function)] = function
_mm.eval( procDef )
return procName
def py2melProc(function,
returnType=None,
procName=None,
evaluateInputs=True,
argTypes=None):
"""This is a work in progress. It generates and sources a mel procedure which wraps the passed
python function. Theoretically useful for calling your python scripts in scenarios where Maya
does not yet support python callbacks.
The function is inspected in order to generate a MEL procedure which relays its
arguments on to the python function. However, Python features a very versatile argument structure whereas
MEL does not.
- python args with default values (keyword args) will be set to their MEL analogue, if it exists.
- normal python args without default values default to strings. If 'evaluteInputs' is True, string arguments passed to the
MEL wrapper proc will be evaluated as python code before being passed to your wrapped python
function. This allows you to include a typecast in the string representing your arg::
myWrapperProc( "Transform('persp')" );
- *args : not yet implemented
- **kwargs : not likely to be implemented
function
This can be a callable python object or the full, dotted path to the callable object as a string.
If passed as a python object, the object's __name__ and __module__ attribute must point to a valid module
where __name__ can be found.
If a string representing the python object is passed, it should include all packages and sub-modules, along
with the function's name: 'path.to.myFunc'
procName
Optional name of the mel procedure to be created. If None, the name of the function will be used.
evaluateInputs
If True (default), string arguments passed to the generated mel procedure will be evaluated as python code, allowing
you to pass a more complex python objects as an argument. For example:
In python:
>>> import pymel.tools.py2mel as py2mel
>>> def myFunc( arg ):
... for x in arg:
... print x
>>> py2mel.py2melProc( myFunc, procName='myFuncWrapper', evaluateInputs=True )
Then, in mel::
// execute the mel-to-python wrapper procedure
myFuncWrapper("[ 1, 2, 3]");
the string "[1,2,3]" will be converted to a python list [1,2,3] before it is executed by the python function myFunc
"""
function = _getFunction(function)
funcName = function.__name__
melCompile = []
melArgs = []
melArrayToStrDecls = []
argList, defaults, description = getMelArgs(function)
if argTypes:
if isMapping(argTypes):
pass
elif isIterable(argTypes):
tmp = argTypes
argTypes = {}
for i, argType in enumerate(tmp):
argTypes[argList[i][0]] = argType
else:
raise ValueError, "argTypes must be iterable or mapping type"
for argType in argTypes.values():
if not isValidMelType(argType):
raise TypeError, "%r is not a valid mel type: %s" % (
argType, ', '.join(MELTYPES))
else:
argTypes = {}
for arg, melType in argList:
melType = argTypes.get(arg, melType)
if melType == 'string':
compilePart = "'\" + $%s + \"'" % arg
melCompile.append(compilePart)
elif melType == None:
melType = 'string'
compilePart = "'\" + $%s + \"'" % arg
compilePart = r'eval(\"\"\"%s\"\"\")' % compilePart
melCompile.append(compilePart)
elif melType.count('[]'):
melArrayToStrDecls.append(
'string $_%s ="("; int $i=0;for($i; $i<size($%s); $i++) { $_%s += ($%s[$i] + ","); } $_%s += ")";'
% (arg, arg, arg, arg, arg))
melCompile.append("'\" + $_%s + \"'" % arg)
else:
melCompile.append("\" + $%s + \"" % arg)
if melType.count('[]'):
melType = melType.replace('[]', '')
melArgs.append('%s $%s[]' % (melType, arg))
else:
melArgs.append('%s $%s' % (melType, arg))
if procName is None:
procName = funcName
procDef = """global proc %s %s( %s ){ %s
python("import %s; %s._functionStore[%r](%s)");}""" % (
returnType if returnType else '', procName,
', '.join(melArgs), ''.join(melArrayToStrDecls), __name__, __name__,
repr(function), ','.join(melCompile))
_functionStore[repr(function)] = function
_mm.eval(procDef)
return procName