Centos7 环境下 Python2.7 换成 Python3.7 运行 scrapy 应用所遇到的问题记录
参考网友的安装过程 Linux系统Centos安装Python3.7
设置Python默认为Python3.7
mv /usr/bin/python /usr/bin/python.bak ln -s /usr/python/bin/python3 /usr/bin/python
问题1:编译安装(make install)时抛错了 ModuleNotFoundError: No module named '_ctypes'
解决方案:
3.7版本需要一个新的包libffi-devel,安装此包之后再次进行编译安装即可。
yum install libffi-devel -y make install
问题2:pip install scrapy 时出现错误 error: command ‘gcc’
原因:由于pip是Python2.7的版本,而在安装过程了默认Python已经是3.7版本了,就是pip和Python版本不一致
解决方案:
添加一个pip3新软件到执行目录,保留原来的pip
# 如果有删掉原来的软连接 rm /usr/bin/pip3 # 重新创建软连接 ln -s /usr/python/bin/pip3 /usr/bin/pip3 # 用pip3安装Python3的应用 pip3 install scrapy
问题3:提示缺少扩展模块(这里个人觉得和PHP的安装环境类似,正常会有一个_sqlite3.so) pip._vendor.packaging.requirements.InvalidRequirement: Invalid requirement, parse error at "'_sqlite3'"
原因:这一步是由于没有搞清楚运行 scrapy 应用需要哪些扩展,首先就需要这个
解决方案:
安装Python3.7前,最好先 yum 安装所需要的依赖『**** 然后重新编译安装Python3.7 ****』,给一个网友给出的依赖,运行通过
yum -y install sqlite-devel gcc libffi-devel openssl-devel libxml2 libxslt-devel libxml2-devel python-devel python-setuptools
问题4: 运行 yum 命令时抛错 'File "/usr/bin/yum", line 30 except KeyboardInterrupt, e:'
原因:因为yum包使用python2*等开发,修该为环境修改python3之后有问题
解决方案:
修改文件 /usr/bin/yum 和 /usr/libexec/urlgrabber-ext-down 头中相应python 为 python2.7,如下 #!/usr/bin/python2.7
问题5:运行 scrapy 遇到 SyntaxError:invalid syntax,在“from twisted.conch import manhole”而且提示符‘^’指向async
原因:Python3.7 这个版本把async变成了关键字
解决方案:
替换掉 python3.7/site-packages/twisted/conch/manhole.py 文件中的 syntax 关键字,修改后的如下:
# -*- test-case-name: twisted.conch.test.test_manhole -*- # Copyright (c) Twisted Matrix Laboratories. # See LICENSE for details. """ Line-input oriented interactive interpreter loop. Provides classes for handling Python source input and arbitrary output interactively from a Twisted application. Also included is syntax coloring code with support for VT102 terminals, control code handling (^C, ^D, ^Q), and reasonable handling of Deferreds. @author: Jp Calderone """ import code, sys, tokenize from io import BytesIO from twisted.conch import recvline from twisted.internet import defer from twisted.python.compat import _tokenize from twisted.python.htmlizer import TokenPrinter class FileWrapper: """ Minimal write-file-like object. Writes are translated into addOutput calls on an object passed to __init__. Newlines are also converted from network to local style. """ softspace = 0 state = 'normal' def __init__(self, o): self.o = o def flush(self): pass def write(self, data): self.o.addOutput(data.replace('\r\n', '\n')) def writelines(self, lines): self.write(''.join(lines)) class ManholeInterpreter(code.InteractiveInterpreter): """ Interactive Interpreter with special output and Deferred support. Aside from the features provided by L{code.InteractiveInterpreter}, this class captures sys.stdout output and redirects it to the appropriate location (the Manhole protocol instance). It also treats Deferreds which reach the top-level specially: each is formatted to the user with a unique identifier and a new callback and errback added to it, each of which will format the unique identifier and the result with which the Deferred fires and then pass it on to the next participant in the callback chain. """ numDeferreds = 0 def __init__(self, handler, locals=None, filename="<console>"): code.InteractiveInterpreter.__init__(self, locals) self._pendingDeferreds = {} self.handler = handler self.filename = filename self.resetBuffer() def resetBuffer(self): """ Reset the input buffer. """ self.buffer = [] def push(self, line): """ Push a line to the interpreter. The line should not have a trailing newline; it may have internal newlines. The line is appended to a buffer and the interpreter's runsource() method is called with the concatenated contents of the buffer as source. If this indicates that the command was executed or invalid, the buffer is reset; otherwise, the command is incomplete, and the buffer is left as it was after the line was appended. The return value is 1 if more input is required, 0 if the line was dealt with in some way (this is the same as runsource()). @param line: line of text @type line: L{bytes} @return: L{bool} from L{code.InteractiveInterpreter.runsource} """ self.buffer.append(line) source = b"\n".join(self.buffer) source = source.decode("utf-8") more = self.runsource(source, self.filename) if not more: self.resetBuffer() return more def runcode(self, *a, **kw): orighook, sys.displayhook = sys.displayhook, self.displayhook try: origout, sys.stdout = sys.stdout, FileWrapper(self.handler) try: code.InteractiveInterpreter.runcode(self, *a, **kw) finally: sys.stdout = origout finally: sys.displayhook = orighook def displayhook(self, obj): self.locals['_'] = obj if isinstance(obj, defer.Deferred): # XXX Ick, where is my "hasFired()" interface? if hasattr(obj, "result"): self.write(repr(obj)) elif id(obj) in self._pendingDeferreds: self.write("<Deferred #%d>" % (self._pendingDeferreds[id(obj)][0],)) else: d = self._pendingDeferreds k = self.numDeferreds d[id(obj)] = (k, obj) self.numDeferreds += 1 obj.addCallbacks(self._cbDisplayDeferred, self._ebDisplayDeferred, callbackArgs=(k, obj), errbackArgs=(k, obj)) self.write("<Deferred #%d>" % (k,)) elif obj is not None: self.write(repr(obj)) def _cbDisplayDeferred(self, result, k, obj): self.write("Deferred #%d called back: %r" % (k, result), True) del self._pendingDeferreds[id(obj)] return result def _ebDisplayDeferred(self, failure, k, obj): self.write("Deferred #%d failed: %r" % (k, failure.getErrorMessage()), True) del self._pendingDeferreds[id(obj)] return failure def write(self, data, async_liugx=False): self.handler.addOutput(data, async_liugx) CTRL_C = b'\x03' CTRL_D = b'\x04' CTRL_BACKSLASH = b'\x1c' CTRL_L = b'\x0c' CTRL_A = b'\x01' CTRL_E = b'\x05' class Manhole(recvline.HistoricRecvLine): """ Mediator between a fancy line source and an interactive interpreter. This accepts lines from its transport and passes them on to a L{ManholeInterpreter}. Control commands (^C, ^D, ^\) are also handled with something approximating their normal terminal-mode behavior. It can optionally be constructed with a dict which will be used as the local namespace for any code executed. """ namespace = None def __init__(self, namespace=None): recvline.HistoricRecvLine.__init__(self) if namespace is not None: self.namespace = namespace.copy() def connectionMade(self): recvline.HistoricRecvLine.connectionMade(self) self.interpreter = ManholeInterpreter(self, self.namespace) self.keyHandlers[CTRL_C] = self.handle_INT self.keyHandlers[CTRL_D] = self.handle_EOF self.keyHandlers[CTRL_L] = self.handle_FF self.keyHandlers[CTRL_A] = self.handle_HOME self.keyHandlers[CTRL_E] = self.handle_END self.keyHandlers[CTRL_BACKSLASH] = self.handle_QUIT def handle_INT(self): """ Handle ^C as an interrupt keystroke by resetting the current input variables to their initial state. """ self.pn = 0 self.lineBuffer = [] self.lineBufferIndex = 0 self.interpreter.resetBuffer() self.terminal.nextLine() self.terminal.write(b"KeyboardInterrupt") self.terminal.nextLine() self.terminal.write(self.ps[self.pn]) def handle_EOF(self): if self.lineBuffer: self.terminal.write(b'\a') else: self.handle_QUIT() def handle_FF(self): """ Handle a 'form feed' byte - generally used to request a screen refresh/redraw. """ self.terminal.eraseDisplay() self.terminal.cursorHome() self.drawInputLine() def handle_QUIT(self): self.terminal.loseConnection() def _needsNewline(self): w = self.terminal.lastWrite return not w.endswith(b'\n') and not w.endswith(b'\x1bE') def addOutput(self, data, async_liugx=False): if async_liugx: self.terminal.eraseLine() self.terminal.cursorBackward(len(self.lineBuffer) + len(self.ps[self.pn])) self.terminal.write(data) if async_liugx: if self._needsNewline(): self.terminal.nextLine() self.terminal.write(self.ps[self.pn]) if self.lineBuffer: oldBuffer = self.lineBuffer self.lineBuffer = [] self.lineBufferIndex = 0 self._deliverBuffer(oldBuffer) def lineReceived(self, line): more = self.interpreter.push(line) self.pn = bool(more) if self._needsNewline(): self.terminal.nextLine() self.terminal.write(self.ps[self.pn]) class VT102Writer: """ Colorizer for Python tokens. A series of tokens are written to instances of this object. Each is colored in a particular way. The final line of the result of this is generally added to the output. """ typeToColor = { 'identifier': b'\x1b[31m', 'keyword': b'\x1b[32m', 'parameter': b'\x1b[33m', 'variable': b'\x1b[1;33m', 'string': b'\x1b[35m', 'number': b'\x1b[36m', 'op': b'\x1b[37m'} normalColor = b'\x1b[0m' def __init__(self): self.written = [] def color(self, type): r = self.typeToColor.get(type, b'') return r def write(self, token, type=None): if token and token != b'\r': c = self.color(type) if c: self.written.append(c) self.written.append(token) if c: self.written.append(self.normalColor) def __bytes__(self): s = b''.join(self.written) return s.strip(b'\n').splitlines()[-1] if bytes == str: # Compat with Python 2.7 __str__ = __bytes__ def lastColorizedLine(source): """ Tokenize and colorize the given Python source. Returns a VT102-format colorized version of the last line of C{source}. @param source: Python source code @type source: L{str} or L{bytes} @return: L{bytes} of colorized source """ if not isinstance(source, bytes): source = source.encode("utf-8") w = VT102Writer() p = TokenPrinter(w.write).printtoken s = BytesIO(source) for token in _tokenize(s.readline): (tokenType, string, start, end, line) = token p(tokenType, string, start, end, line) return bytes(w) class ColoredManhole(Manhole): """ A REPL which syntax colors input as users type it. """ def getSource(self): """ Return a string containing the currently entered source. This is only the code which will be considered for execution next. """ return (b'\n'.join(self.interpreter.buffer) + b'\n' + b''.join(self.lineBuffer)) def characterReceived(self, ch, moreCharactersComing): if self.mode == 'insert': self.lineBuffer.insert(self.lineBufferIndex, ch) else: self.lineBuffer[self.lineBufferIndex:self.lineBufferIndex+1] = [ch] self.lineBufferIndex += 1 if moreCharactersComing: # Skip it all, we'll get called with another character in # like 2 femtoseconds. return if ch == b' ': # Don't bother to try to color whitespace self.terminal.write(ch) return source = self.getSource() # Try to write some junk try: coloredLine = lastColorizedLine(source) except tokenize.TokenError: # We couldn't do it. Strange. Oh well, just add the character. self.terminal.write(ch) else: # Success! Clear the source on this line. self.terminal.eraseLine() self.terminal.cursorBackward(len(self.lineBuffer) + len(self.ps[self.pn]) - 1) # And write a new, colorized one. self.terminal.write(self.ps[self.pn] + coloredLine) # And move the cursor to where it belongs n = len(self.lineBuffer) - self.lineBufferIndex if n: self.terminal.cursorBackward(n)
问题6:部署问题,将线下的代码直接拉上来直接运行会抛出 scrapy UserWarning: Error detecting parent module: FileNotFoundError(2, 'No 这样的异常
解决方案:
将创建项目、创建spider的命令在根目录在运行一遍,然后拿线下的文件覆盖到线上,再运行命令时正常运行