TypeError:字符串索引必须是整数，而不是NoneTyp

Question

Stackoverflow每次都会剪切邮件的这部分。。无论如何：我正在尝试在python中创建一种特殊的搜索函数。基本上它忽略了大小写和空格。“和”也被认为是相等的。所有的工作都很好，我能够打开一个文本文件，找到“路径”一词。但当我试图寻找“d=\”时，我得到了一个非常奇怪的错误。显然我在用一个非类型变量索引一个字符串。。。但是上面的7行我用完全相同的方式索引它，在那里它工作！！你知道吗

这是我的密码

import wx

class Mywin(wx.Frame):
    def __init__(self, parent, title):
        super(Mywin, self).__init__(parent, title = title,size = (400, 200))

        self.panel = wx.Panel(self)
        vbox = wx.BoxSizer(wx.VERTICAL)

        self.bButton = wx.Button(self.panel, -1, "Vector bestand kiezen", pos=(10, 10))
        self.bButton.Bind(wx.EVT_BUTTON, self.bButton_clicked)

        self.sb = self.CreateStatusBar()

        self.panel.SetSizer(vbox)
        self.panel.Layout()

        self.Centre()
        self.Show()
        self.Fit()

    def bButton_clicked(self, event):
        with wx.FileDialog(self, "Open vector file", wildcard="Scalable vector graphic (*.svg)|*.svg|Drawing exchange format (*.dxf)|*.dxf", style=wx.FD_OPEN | wx.FD_FILE_MUST_EXIST) as fileDialog:

            if fileDialog.ShowModal() == wx.ID_CANCEL:
                return     # the user changed their mind

            # Proceed loading the file chosen by the user
            self.pathname = fileDialog.GetPath()
            self.sb.SetStatusText("File was opened. Finding separated paths.")
            self.extractPaths()
        return

    def specialFind(self, sIndex, substring):
        eIndex = sIndex
        findingStart = 1
        i = int(0)
        while(i < len(substring)):
            print("i: {}".format(i))
            if(i == 0):
                print("looking for the start")
                findingStart = 1
            else:
                findingStart = 0
            if(substring[i] == "\'"):
                while(1):
                    if((self.text[eIndex] == "\'") | (self.text[eIndex] == "\"")):
                        print(self.text[eIndex])
                        eIndex = eIndex + 1
                        break
                    elif((self.text[eIndex] == " ") | (findingStart == 1)):
                        eIndex = eIndex + 1
                        if(eIndex == len(self.text)):
                            return -1
                        continue
                    else:
                        eIndex = eIndex + 1
                        i = -1
                        break
            elif((ord(substring[i]) >= 65) & (ord(substring[i]) <= 122)):
                print("Looking for the letter: {}".format(substring[i]))
                if(ord(substring[i]) <= 90):
                    sign = 1
                else:
                    sign = -1
                while(1):
                    print("{}, type: {}".format(eIndex, type(eIndex)))
                    if( ord(self.text[eIndex]) == ord(substring[i]) ): 
                    # | (ord(self.text[eIndex]) ==  ord(substring[i]) + sign * 32)):
                        print("{}:: {}".format(self.text[eIndex], eIndex))
                        eIndex = eIndex + 1
                        break
                    elif((ord(self.text[eIndex]) == ord(" ")) | (findingStart == 1)):
                        print("{} != {}".format(ord(self.text[eIndex]), ord(substring[i])))
                        eIndex = eIndex + 1
                        if(eIndex == len(self.text)):
                            print("searched whole document")
                            return -1
                        continue
                    else:
                        print("{} != {}".format(self.text[eIndex], substring[i]))
                        print("trying again")
                        eIndex = eIndex + 1
                        i = -1
                        break
            else:
                while(1):
                    if(ord(self.text[eIndex]) ==  ord(substring[i])):
                        print("{}:: {}".format(self.text[eIndex], eIndex))
                        eIndex = eIndex + 1
                        break
                    elif((ord(self.text[eIndex]) == ord(" ")) | (findingStart == 1)):
                        eIndex = eIndex + 1
                        if(eIndex == len(self.text)):
                            return -1
                        continue
                    else:
                        eIndex = eIndex + 1
                        i = -1
                        break
            i = i + 1

    def extractPaths(self):
        self.pathAmount = 0

        file = open(self.pathname, "r")
        self.text = file.read()
        self.textLength = len(self.text)

        pathIndex = 0
        dsIndex = 0
        deIndex = 0

        while(1):
            pathIndex = self.specialFind(deIndex, "<path")
            if(pathIndex == -1):
                print("No path found this time.")
                break
            dsIndex = self.specialFind(pathIndex, "d=\"")
            deIndex = self.specialFind(dsIndex, "\"")
            if((dsIndex == -1) | (deIndex == -1)):
                self.sb.SetStatusText("File is corrupted. Path tag was opened, but never properly closed.")
                break
            self.pathAmount = self.pathAmount + 1

        print("pathAmount: {}".format(self.pathAmount))

        return

print("<: {}".format(ord('<')))
# print("a: {}, A: {}".format(ord('a'), ord('A')))
# for i in range(ord('A'), ord('z') + 6):
    # print("{}".format(chr(i)))

app = wx.App() 
Mywin(None,  'Vector splitter.')
app.MainLoop()

这是我要打开的文件：

<?xml version="1.0" standalone="no"?>
<!DOCTYPE svg PUBLIC "-//W3C//DTD SVG 1.1//EN" "http://www.w3.org/Graphics/SVG/1.1/DTD/svg11.dtd">
<svg width="4" height="4" viewBox="-2 -2 4 4" xmlns="http://www.w3.org/2000/svg" version="1.1">
<title>OpenSCAD Model</title>
<path d="
M 2,-0 L -1,-1.73205 L -1,1.73205 z
" stroke="black" fill="lightgray" stroke-width="0.5"/></svg>

这是一个SVG，我正试图将其拆分为断开连接的多边形，以保存到单独的SVG文件中。你知道吗

这是python脚本给我的输出：

C:\Users\Anteino\Desktop\python svg splitter>python gui.py
<: 60
i: 0
looking for the start
<:: 0
i: 1
Looking for the letter: p
1, type: <type 'int'>
t != p
trying again
i: 0
looking for the start
<:: 21
i: 1
Looking for the letter: p
22, type: <type 'int'>
/ != p
trying again
i: 0
looking for the start
<:: 30
i: 1
Looking for the letter: p
31, type: <type 'int'>
p:: 31
i: 2
Looking for the letter: a
32, type: <type 'int'>
a:: 32
i: 3
Looking for the letter: t
33, type: <type 'int'>
t:: 33
i: 4
Looking for the letter: h
34, type: <type 'int'>
h:: 34
i: 0
looking for the start
Looking for the letter: d
None, type: <type 'NoneType'>
Traceback (most recent call last):
  File "gui.py", line 31, in bButton_clicked
    self.extractPaths()
  File "gui.py", line 119, in extractPaths
    dsIndex = self.specialFind(pathIndex, "d=\"")
  File "gui.py", line 68, in specialFind
    if( ord(self.text[eIndex]) == ord(substring[i]) ):
TypeError: string indices must be integers, not NoneType

我真的不明白。有什么想法吗？你知道吗

Answer 1

正如Michael已经指出的，specialFind不会返回int，python也不会警告您要返回的变量类型。有一次，python的宽容性格并不那么实际。你知道吗