Reboot运维开发Python-05.pptxVIP

RebootPython 5高级语法12Homework show3复习class4复习装饰器@A def B:pass 等价于 def B:pass B=A(B)即将函数B作为参数传给参数A 5复习import MySQLdbdb=MySQLdb.connect(user=reboot, passwd=reboot123,db=reboot,charset=utf8)db.autocommit(True) /doc/refman/5.1/en/innodb-transaction-model.htmlInnoDB transaction model c = db.cursor()c.execute(select * from students)students = c.fetchall()((1L, u\u5c0f\u5367\u5e95, 1, uwodi), (2L, u\u96ea\u7cd5, 1, uxuegao))6复习Flask7再谈装饰器@只用大致了解原理，会用大神写的装饰器#超时函数import signal,functoolsclass TimeoutError(Exception): passdef timeout(seconds, error_message = Function call timed out): def decorated(func): def _handle_timeout(signum, frame): raise TimeoutError(error_message) def wrapper(*args, **kwargs): signal.signal(signal.SIGALRM, _handle_timeout) signal.alarm(seconds) try: result = func(*args, **kwargs) finally: signal.alarm(0) return result return functools.wraps(func)(wrapper) return decorated8再谈装饰器#超时函数In [15]: slow_function()-------------------------------------------------------------------TimeoutError Traceback (most recent call last)9再谈装饰器#traceimport sys,os,linecachedef trace(f): def globaltrace(frame, why, arg): if why == “call: return localtrace return None def localtrace(frame, why, arg): if why == line: # record the file name and line number of every trace filename = frame.f_code.co_filename lineno = frame.f_lineno bname = os.path.basename(filename) print {}({}): {}.format( bname, lineno, linecache.getline(filename, lineno)), return localtrace def _f(*args, **kwds): sys.settrace(globaltrace) result = f(*args, **kwds) sys.settrace(None) return result return _f10再谈装饰器#traceIn [12]: @trace ....: def xxx(): ....: print 1 ....: print 22 ....: print 333 ....:In [13]: xxx()ipython-input-12-8c8ff1296589(3): print 11ipython-input-12-8c8ff1296589(4): print 2222ipython-input-12-8c8ff1296589(5): print定长参数懂得意思即可，不要求会写参数格式为 *para 表示接受一个元组为 **para 表示接受一个字典*para要在**para之前 12不定长参数懂得意思即可，不要求会写参数格式为 *para 表示接受一个元组为 **para 表示接受一个字典