[英]Raising error with non-BMP characters restarts shell
我正在編寫一個 python 模塊,用於在 pygame 中顯示和輸入表情符號。 這意味着我經常使用非 BMP Unicode 字符,顯然 python shell 不喜歡。
我制作了一個自定義的類似字符串的對象,通過將表情符號序列存儲為單個字符來更輕松地處理表情符號字符和序列。 然而,雖然我希望 str(self) 返回對象的原始 Unicode 表示,但這會在嘗試打印時導致問題,或者更糟糕的是,當它包含在錯誤消息中時。
這是錯誤消息中包含非 BMP 字符時發生的情況的示例。 在 Windows 10 上運行 Python 3.7.3。
>>> raise ValueError('Beware the non-BMP! \U0001f603')
Traceback (most recent call last):
File "<pyshell#0>", line 1, in <module>
raise ValueError('Beware the non-BMP! \U0001f603')
Traceback (most recent call last):
File "<pyshell#0>", line 1, in <module>
raise ValueError('Beware the non-BMP! \U0001f603')
Traceback (most recent call last):
File "D:\Python37\lib\idlelib\run.py", line 474, in runcode
exec(code, self.locals)
File "<pyshell#0>", line 1, in <module>
Traceback (most recent call last):
File "D:\Python37\lib\idlelib\run.py", line 474, in runcode
exec(code, self.locals)
File "<pyshell#0>", line 1, in <module>
ValueError:
During handling of the above exception, another exception occurred:
Traceback (most recent call last):
File "D:\Python37\lib\idlelib\run.py", line 144, in main
ret = method(*args, **kwargs)
File "D:\Python37\lib\idlelib\run.py", line 486, in runcode
print_exception()
File "D:\Python37\lib\idlelib\run.py", line 234, in print_exception
print_exc(typ, val, tb)
File "D:\Python37\lib\idlelib\run.py", line 232, in print_exc
print(line, end='', file=efile)
File "D:\Python37\lib\idlelib\run.py", line 362, in write
return self.shell.write(s, self.tags)
File "D:\Python37\lib\idlelib\rpc.py", line 608, in __call__
value = self.sockio.remotecall(self.oid, self.name, args, kwargs)
File "D:\Python37\lib\idlelib\rpc.py", line 220, in remotecall
return self.asyncreturn(seq)
File "D:\Python37\lib\idlelib\rpc.py", line 251, in asyncreturn
return self.decoderesponse(response)
File "D:\Python37\lib\idlelib\rpc.py", line 271, in decoderesponse
raise what
UnicodeEncodeError: 'UCS-2' codec can't encode characters in position 32-32: Non-BMP character not supported in Tk
During handling of the above exception, another exception occurred:
Traceback (most recent call last):
File "D:\Python37\lib\idlelib\run.py", line 158, in main
print_exception()
File "D:\Python37\lib\idlelib\run.py", line 234, in print_exception
print_exc(typ, val, tb)
File "D:\Python37\lib\idlelib\run.py", line 220, in print_exc
print_exc(type(context), context, context.__traceback__)
File "D:\Python37\lib\idlelib\run.py", line 232, in print_exc
print(line, end='', file=efile)
File "D:\Python37\lib\idlelib\run.py", line 362, in write
return self.shell.write(s, self.tags)
File "D:\Python37\lib\idlelib\rpc.py", line 608, in __call__
value = self.sockio.remotecall(self.oid, self.name, args, kwargs)
File "D:\Python37\lib\idlelib\rpc.py", line 220, in remotecall
return self.asyncreturn(seq)
File "D:\Python37\lib\idlelib\rpc.py", line 251, in asyncreturn
return self.decoderesponse(response)
File "D:\Python37\lib\idlelib\rpc.py", line 271, in decoderesponse
raise what
UnicodeEncodeError: 'UCS-2' codec can't encode characters in position 32-32: Non-BMP character not supported in Tk
During handling of the above exception, another exception occurred:
Traceback (most recent call last):
File "<string>", line 1, in <module>
File "D:\Python37\lib\idlelib\run.py", line 162, in main
traceback.print_exception(type, value, tb, file=sys.__stderr__)
File "D:\Python37\lib\traceback.py", line 105, in print_exception
print(line, file=file, end="")
File "D:\Python37\lib\idlelib\run.py", line 362, in write
return self.shell.write(s, self.tags)
File "D:\Python37\lib\idlelib\rpc.py", line 608, in __call__
value = self.sockio.remotecall(self.oid, self.name, args, kwargs)
File "D:\Python37\lib\idlelib\rpc.py", line 220, in remotecall
return self.asyncreturn(seq)
File "D:\Python37\lib\idlelib\rpc.py", line 251, in asyncreturn
return self.decoderesponse(response)
File "D:\Python37\lib\idlelib\rpc.py", line 271, in decoderesponse
raise what
UnicodeEncodeError: 'UCS-2' codec can't encode characters in position 32-32: Non-BMP character not supported in Tk
=============================== RESTART: Shell ===============================
如您所見,shell 似乎進入了一個無限循環以嘗試處理錯誤,然后重新啟動 shell 以防止卡住。 有什么辦法可以 a) 使str對錯誤處理程序的工作方式不同,或者 b) 防止 shell 重新啟動以便正確顯示錯誤?
從snakecharmerb 和這兩個問題中獲取想法,我已經實現了一些代碼來檢查模塊是否正在IDLE 中運行,如果是,則該函數是否正在被錯誤處理程序調用。 測試似乎工作正常。 我有以下檢查空閑運行環境
IN_IDLE = False
for item in ['idlelib.__main__','idlelib.run','idlelib']:
IN_IDLE = IN_IDLE or item in sys.modules
下面是新的__str__
函數
def __str__(self):
""" Return str(self). """
if IN_IDLE:
# Check for caller. If string is being printed, modify
# output to be IDLE-friendly (no non-BMP characters)
callername = sys._getframe(1).f_code.co_name
if callername == '_some_str':
rstr = ''
for char in self.__raw:
if ord(char) > 0xFFFF:
rstr += '\\U'+hex(ord(char))[2:].zfill(8)
else:
rstr += repr(char)[1:-1]
return rstr
else:
return self.__raw
else:
return self.__raw
其中self.__raw
保存對象的原始文本表示。 我緩存它是為了提高效率,因為對象是不可變的。
當然,雖然這確實解決了這個問題,但我覺得 python 不應該在發生這種情況時重新啟動整個 shell。 將在 bugs.python.org 上發布
編輯:作為問題 36698發布在bugs.python.org 上
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