Question

我正在尝试在Maya中编写一个用户界面，并且它与多个级别的父级并且没有缩进令人难以置信地混淆。基本代码（没有任何功能）目前大约有400行，需要一段时间才能找到我需要的位。

例如，在没有注释的情况下使用以下代码：

#Earlier user interface

py.rowColumnLayout( numberOfColumns = 5 )
py.text( label="", width = 1 )
py.text( label="Column 1", enable = False, width = 250 )
py.text( label="", width = 1 )
py.text( label="Column 2" enable = False, width = 250 )
py.text( label="", width = 1 )

py.text( label="" )
py.rowColumnLayout( numberOfColumns = 4 )
py.text( label="   Input data:", align="left" )
py.text( label="" )
py.text( label="" )
py.text( label="" )
py.textField( text = "Text here" )
py.text( label="" )
py.text( label="" )
py.text( label="" )
py.setParent( ".." )

py.text( label="" )
py.rowColumnLayout( numberOfColumns = 4 )
py.rowColumnLayout( numberOfColumns = 5 )
py.radioButton( label = "Read file from path", width = 100 )
py.text( label="" )
py.button( label = "Browse" )
py.text( label="" )
py.button( label = "Validate" )
py.setParent( ".." )
py.text( label="" )
py.text( label="" )
py.text( label="" )
py.setParent( ".." )
py.setParent( ".." )

但是，这就是缩进的外观

py.rowColumnLayout( numberOfColumns = 5 )
    py.text( label="", width = 1 )
    py.text( label="Column 1", enable = False, width = 250 )
    py.text( label="", width = 1 )
    py.text( label="Column 2" enable = False, width = 250 )
    py.text( label="", width = 1 )

    py.text( label="" )
    py.rowColumnLayout( numberOfColumns = 4 )
        py.text( label="   Input data:", align="left" )
        py.text( label="" )
        py.text( label="" )
        py.text( label="" )
        py.textField( text = "Text here" )
        py.text( label="" )
        py.text( label="" )
        py.text( label="" )
        py.setParent( ".." )

    py.text( label="" )
    py.rowColumnLayout( numberOfColumns = 4 )
        py.rowColumnLayout( numberOfColumns = 5 )
            py.radioButton( label = "Read file from path", width = 100 )
            py.text( label="" )
            py.button( label = "Browse" )
            py.text( label="" )
            py.button( label = "Validate" )
            py.setParent( ".." )
        py.text( label="" )
        py.text( label="" )
        py.text( label="" )
        py.setParent( ".." )
    py.setParent( ".." )

有什么办法我可以用缩进写它但是让它在执行时忽略它们吗？我看到了一个问题，问你是否可以在没有缩进的情况下编写python，但我有点需要相反。

注意：某些py.*函数的输出值也需要分配给变量，因为布局需要先排序，所以还没有。

Answer 1

这是一个很好的用例，像我们这样的技术艺术家每天都会在Maya中构建UI。

对于基于PyMEL的UI：

这内置于PyMEL中。您不必创建上下文管理器。布局命令本身是上下文管理器。您只需在每个布局命令调用之前添加with关键字，如下所示：

# Do this when using PyMEL for your UI code
import pymel.core as pm

# ...

with pm.rowColumnLayout( numberOfColumns = 5 ):
    pm.text( label="", width = 1 )
    pm.text( label="Column 1", enable = False, width = 250 )
    pm.text( label="", width = 1 )
    pm.text( label="Column 2", enable = False, width = 250 )
    pm.text( label="", width = 1 )

    pm.text( label="" )

    with pm.rowColumnLayout( numberOfColumns = 4 ):
        pm.text( label="   Input data:", align="left" )
        pm.text( label="" )
        pm.text( label="" )
        pm.text( label="" )
        pm.textField( text = "Text here" )
        pm.text( label="" )
        pm.text( label="" )
        pm.text( label="" )        

    pm.text( label="" )
    with pm.rowColumnLayout( numberOfColumns = 4 ):
        with pm.rowColumnLayout( numberOfColumns = 5 ):
            pm.radioButton( label = "Read file from path", width = 100 )
            pm.text( label="" )
            pm.button( label = "Browse" )
            pm.text( label="" )
            pm.button( label = "Validate" )

        pm.text( label="" )
        pm.text( label="" )
        pm.text( label="" )

对于基于maya.cmds的UI：

一个快速的解决方案是创建一个虚拟上下文管理器。你可以做这样的事情

# Do this when using Maya's cmds for your UI code
import maya.cmds as cmds

# ...

from contextlib import contextmanager
@contextmanager
def neat_indent():
    # OPTIONAL: This is also an opportunity to do something before the block of code runs!
    try:
        # During this is where your indented block will execute
        # Leave it empty
        yield
    finally:
        # OPTIONAL: This is where you can write code that executes AFTER your indented block executes.
        pass

这样你的代码就不必改变太多了。只需在每个预期缩进的开头添加with关键字的上下文管理器功能！

cmds.rowColumnLayout( numberOfColumns = 5 )
with neat_indent():
    cmds.text( label="", width = 1 )
    cmds.text( label="Column 1", enable = False, width = 250 )
    cmds.text( label="", width = 1 )
    cmds.text( label="Column 2", enable = False, width = 250 )
    cmds.text( label="", width = 1 )

    cmds.text( label="" )

    cmds.rowColumnLayout( numberOfColumns = 4 )
    with neat_indent():
        cmds.text( label="   Input data:", align="left" )
        cmds.text( label="" )
        cmds.text( label="" )
        cmds.text( label="" )
        cmds.textField( text = "Text here" )
        cmds.text( label="" )
        cmds.text( label="" )
        cmds.text( label="" )
        cmds.setParent( ".." )

    cmds.text( label="" )
    cmds.rowColumnLayout( numberOfColumns = 4 )
    with neat_indent():
        cmds.rowColumnLayout( numberOfColumns = 5 )
        with neat_indent():
            cmds.radioButton( label = "Read file from path", width = 100 )
            cmds.text( label="" )
            cmds.button( label = "Browse" )
            cmds.text( label="" )
            cmds.button( label = "Validate" )
            cmds.setParent( ".." )
        cmds.text( label="" )
        cmds.text( label="" )
        cmds.text( label="" )
        cmds.setParent( ".." )
    cmds.setParent( ".." )

我们创建的上下文管理器neat_indent()也让您有机会编写包装缩进块的代码。这里的一个实际例子是，在每个缩进的最后，你发现自己正在编写py.setParent("..")。您可以将其放入上下文管理器的finally部分：

from contextlib import contextmanager
@contextmanager
def neat_indent(parent=None):
    # OPTIONAL: This is also an opportunity to do something before the block of code runs!
    try:
        # During this is where your indented block will execute
        # Leave it empty
        yield
    finally:
        # OPTIONAL: This is where you can write code that executes AFTER your indented block executes.
        if parent:
            cmds.setParent(parent)

您的代码现在更有意义了：

cmds.rowColumnLayout( numberOfColumns = 5 )
with neat_indent(".."):
    cmds.text( label="", width = 1 )
    cmds.text( label="Column 1", enable = False, width = 250 )
    cmds.text( label="", width = 1 )
    cmds.text( label="Column 2", enable = False, width = 250 )
    cmds.text( label="", width = 1 )

    cmds.text( label="" )

    cmds.rowColumnLayout( numberOfColumns = 4 )
    with neat_indent(".."):
        cmds.text( label="   Input data:", align="left" )
        cmds.text( label="" )
        cmds.text( label="" )
        cmds.text( label="" )
        cmds.textField( text = "Text here" )
        cmds.text( label="" )
        cmds.text( label="" )
        cmds.text( label="" )        

    cmds.text( label="" )
    cmds.rowColumnLayout( numberOfColumns = 4 )
    with neat_indent(".."):
        cmds.rowColumnLayout( numberOfColumns = 5 )
        with neat_indent(".."):
            cmds.radioButton( label = "Read file from path", width = 100 )
            cmds.text( label="" )
            cmds.button( label = "Browse" )
            cmds.text( label="" )
            cmds.button( label = "Validate" )

        cmds.text( label="" )
        cmds.text( label="" )
        cmds.text( label="" )

上下文管理器很强大。在这篇文章中，我使用了contextmanager标准库模块中的contextlib装饰器。您可以阅读有关此技术here的信息。一般为here with。{/ p>

此外，为了达到这个目的（其中一个目的），在Maya中进行UI开发更清洁，更多Pythonic @theodox创建了mGui模块。看看吧。

Answer 2

您可以在执行代码之前预处理代码行，如图所示：

mycode = """\
    print "something"
        print "something else"
      print 42
    """

exec('\n'.join(line.lstrip() for line in mycode.splitlines()))

输出：

something
something else
42

它甚至可以被制成“一线”：

exec('\n'.join(line.lstrip() for line in """\
    print "something"
        print "something else"
      print 42
    """.splitlines()))

您可以通过以下方式将代码保存在单独的文件中（这样可以使编辑器对其进行语法处理）：

档案mycode.py：

print "something"
    print "something else"
  var = 42

单独文件版本：

with open('mycode.py') as code:
    exec(''.join(line.lstrip() for line in code))
print 'var:', var

输出：

something
something else
var: 42

警告：我应该指出，这些都会从每一行中删除所有缩进，这会弄乱任何遇到的多行Python代码（如if/else） - 这可能会限制其有用性取决于你正在做什么。

Answer 3

@ Kartik的回答很好地涵盖了基础。我指出，通过允许上下文管理器在线声明布局（rowLayout，columnLayout等），你可以更多地清理布局代码，这使得它更容易：

class uiCtx(object):
   '''
   quickie layouthelper: automatically setParents after a layout is finished
   '''
   def __init__(self, uiClass, *args, **kwargs):
        self.Control = uiClass(*args, **kwargs)

    def __enter__(self):
        return self

    def __exit__(self, tb, val, traceback):
        cmds.setParent("..")

    def __repr__(self):
        return self.Control

会在遇到时调用maya.cmds布局函数，然后在缩进块的末尾关闭父级，这样就可以像在此片段中一样进行布局调用

    with uiCtx(cmds.rowLayout, **layout_options) as widget:
        self.Toggle = cmds.checkBox('', v = self.Module.enabled, cc = self._state_changed)
        with uiCtx(cmds.columnLayout, w=self.COLUMNS[1], cal='left') as details:
            cmds.text(l = self.ModuleKey, fn = "boldLabelFont")
            cmds.text(l = self.Module.path, fn = "smallObliqueLabelFont")
        cmds.button("edit",  c=self._edit)
        cmds.button("show", c=self._show)
    return widget

将__repr__添加到uiCtx可让您将其视为像普通maya布局命令一样返回字符串，因此在该示例中，可以通常的方式查询“窗口小部件”。

整个事情是up on GitHub在上下文中看到它。正如Kartik还指出，mGui的形式有一个更精细的声明性UI选项，在实践中看起来像这样：

with gui.Window('window', title = 'fred') as example_window:
    with BindingContext() as bind_ctx:
        with VerticalForm('main') as main:
            Text(None, label = "The following items don't have vertex colors")
            lists.VerticalList('lister' ).Collection < bind() < bound  
            with HorizontalStretchForm('buttons'):
                Button('refresh', l='Refresh')
                Button('close', l='Close')

# show the window
example_window.show()

还有一些与maya布局相关的信息here

Answer 4

创建另一个程序来解析并执行script.py：

parse.py

text = open('script.py').readlines()
text = [i.strip() for i in text]

edit = open('new.py', 'w')
for line in text:
    edit.write(line + '\n')
edit.close()

execfile('new.py')

此文件创建一个将被执行的修改后的new.py。

Answer 5

我可以想到两种可能性，允许您直接编写代码而无需从文本中解析它（语法着色完整，没有临时文件）。

第一种方法是将真理加到每一行的开头，如上面建议的if True:，或者等效地，可能是这样的：

# ...

if 'level 1':  a = py.text( label="" )
if 'level 2':      b = py.rowColumnLayout( numberOfColumns = 4 )
if 'level 3':          c = py.rowColumnLayout( numberOfColumns = 5 )
if 'level 4':              d = py.radioButton( label = "Read file from path", width = 100 )

# ...

如果您不使用评估为False的字符串（例如''），您可以将这些字符串用作评论，以帮助您记住您的GUI的哪个部分。在任何给定的线上重建（用适当数量的空格填充，以确保事物仍然排成一行）。

第二个想法是创建一个包含callables及其参数的容器列表，然后按照你喜欢的方式格式化，然后在最后执行每一个：

objects = {}
commands = [

    # ...

    dict( name = 'spam', func = py.text, label="" ),
    dict( name = 'ham', func = py.rowColumnLayout, numberOfColumns = 4 ),
        dict( name = 'eggs', func = py.rowColumnLayout, numberOfColumns = 5 ),
            dict( name = 'beans', func = py.radioButton, label = "Read file from path", width = 100 ),

    # ...
]

for d in commands:
    objects[ d.pop( 'name' ) ] = d.pop( 'func' )( **d )

Answer 6

使用声明式方法：

interface = [
  [py.rowColumnLayout, [], dict(numberOfColumns=5)],
     [py.text, [], dict(label="", width=1)],
     [py.text, [], dict(label="Column 1", enable=False, width=250)],
     ...
     [py.setParent, [".."], {}],
]    

for callable, args, kwargs in interface:
    callable(*args, **kwargs)

内部()或[]缩进无关紧要，因此您可以根据需要自由组织这些行。

有没有办法缩进Python而不影响代码

6 个答案:

对于基于PyMEL的UI：

对于基于maya.cmds的UI：