Some simple dialogs of wxPython

　　以下四個是我常用的wxPython對話框(或許之後還會陸續增加)，包成函數形式省卻了部分填參數與開啟對話框，消除(Destroy)對話框的動作。

import wx

def SingleChoiceGetDialog(wnd, ItemNameList, dlgTitle = "", hintString = ""):
    """\
SingleChoiceGetDialog(wnd, ItemNameList, dlgTitle = "", hintString = "")
    Get selected index in given items.

    Parameters:
        wnd          ( type = parent window )
        ItemNameList ( type = list of string )
        dlgTitle     ( type = string )
        hintString   ( type = string )
    Returns:
        selectedIndex( type = int or None )"""  
    dlg = wx.SingleChoiceDialog(
            wnd, hintString, dlgTitle,
            ItemNameList,
            wx.CHOICEDLG_STYLE
            )

    if dlg.ShowModal() == wx.ID_OK:
        selectedIndex = dlg.GetSelection()
    else: selectedIndex = None
    dlg.Destroy()
    return selectedIndex

def FilePathGet(wnd, op, wildcard, dlgTitle):
    wildcard = "|".join(["""%s file (*.%s)|*.%s"""%(fileType, subName, subName)
                         for (fileType, subName) in wildcard])

    style = (wx.SAVE | wx.CHANGE_DIR) if op == "save" else (wx.OPEN | wx.CHANGE_DIR)
    FileDlg = wx.FileDialog( wnd, dlgTitle,
                             defaultDir="",
                             defaultFile="",
                             wildcard = wildcard,
                             style=style
                           )

    if( FileDlg.ShowModal() == wx.ID_OK ):
        filePath = FileDlg.GetPath()
    else: filePath = None
    FileDlg.Destroy()
    return filePath

def FileOpenPathGetDialog(wnd, wildcard = [("All","*")], dlgTitle = "File Open"):
    """\
FileOpenPathGetDialog(wnd, wildcard = [("All","*")], dlgTitle = "File Open")
    Get selected file path on action of "FileOpen".

    Parameters:
        wnd          ( type = parent window )
        wildcard     ( type = list of tuple )
        dlgTitle     ( type = string )
    Returns:
        filePath     ( type = string or None)""" 
    return FilePathGet(wnd, "open", wildcard, dlgTitle)

def FileSavePathGetDialog(wnd, wildcard = [("All","*")], dlgTitle = "File Save"):
    """\
FileSavePathGetDialog(wnd, wildcard = [("All","*")], dlgTitle = "File Save")
    Get selected file path on action of "FileSave".

    Parameters:
        wnd          ( type = parent window )
        wildcard     ( type = list of tuple )
        dlgTitle     ( type = string )
    Returns:
        filePath     ( type = string or None )"""     
    return FilePathGet(wnd, "save", wildcard, dlgTitle)

def ErrorMessageDialog(wnd, msg):
    """\
ErrorMessageDialog(wnd, msg)
    Popup an error message.

    Parameters:
        wnd          ( type = parent window )
        msg          ( type = string )""" 
    dlg = wx.MessageDialog(wnd, msg, "Error", wx.OK | wx.ICON_ERROR )
    dlg.ShowModal()
    dlg.Destroy()

　　SingleChoiceGetDialog：從ItemNameList中單選。

　　FileOpenPathGetDialog, FileSavePathGetDialog：取得"開檔"/"存檔"的檔案路徑。
　　　　想顯示副檔名為"py"的檔案("*.py")，就在加入wildcard中加入tuple ("py","py")，前一個"py"是提示字串，後一個"py"是用來過濾副檔名的字串。

　　ErrorMessageDialog：彈出錯誤訊息。

　　對於ＧＵＩ，我傾向花越少時間處理越好；漂亮，獨特的外觀是不太在乎的，只要個普通的window類型的表現，能讓使用者了解的動作提示，例如一看就知道這是要開啟檔案，就足夠了。所以我用了許多預設參數簡化函數呼叫。例如在frame中開啟檔案--

filePath = FileOpenPathGetDialog(self)  # "self" is frame object in this case
if filePath: data = open(filePath,"w")

cPickle - 儲存python物件至檔案 / 從檔案中讀取python物件

cPickle可以在檔案中保存python物件，讀取時不用再另外寫parser重組資訊。

import cPickle

def ObjectSaveToFile(filePath, obj):
    """\
ObjectSaveToFile(filePath, obj)
    Save a python object into file.

    Parameters:
        filePath     ( type = string)
        obj          ( type = any python object like dict )"""
    fileGen = open(filePath, 'w')
    cPickle.dump(obj, fileGen, True)
    fileGen.close()

def ObjectLoadFromFile(filePath):
    """\
ObjectSaveToFile(filePath, obj)
    Load a python object from file.
    Parameters:
        filePath     ( type = string)
    Returns:
        obj          ( type = any python object like list, dict )"""
    fileRead = open(filePath, 'r')
    obj = cPickle.load(fileRead)
    fileRead.close()
    return obj

ObjectSaveToFile函數設計成在檔案中保存單一物件。雖然cPickle支援儲存多個物件至檔案中，但讀取時也得照順序讀。這會造成程式維護的相容性問題：當改變讀取或存入物件順序後，舊的檔案便無法再讀取，或是得特別保留讀取舊檔案格式的程式碼。

因此我會以字典(dict)物件將多個物件包成單一物件，以key來讀取各別物件。objDict.get(key, defaultObj)可用來保持與舊檔案格式的相容，當沒有找到某個key時，將對應物件設定成預設值。

A test for syntaxhighlighter

before...

for i in range(10):
print "hello"

=====

after...

for i in range(10):
    print "hello"