python学习代码
#!/bin/python #example 1.1 #applay def function(a,b): print(a,b) def example1(): apply(function, ("whither","cannada?")) apply(function, (1,2+3)) apply(function, (32,),{"b":"hello world"}) apply(function, (), {"a":"hello world","b":"new world, new way"}) class Rectangle: def __init__(self, color="white", width=10, height=10): print("create a", color, self, "sized", width, "x", height) class RoundedRectangle(Rectangle): def __init__(self, **kw): apply(Rectangle.__init__, (self,), kw) def example2(): rect = Rectangle(color="green", height=100, width=100) rect = RoundedRectangle(color="blue", height=20,width=10) def function2(**kwargs): print(kwargs) apply(function,(),kwargs) def function3(*args): print(args) apply(function, args) def example3(): function3(1,2) function2(a="ddd",b=3) #exmaple 4 def getfunctionbyname(module_name, function_name): module = __import__(module_name) return getattr(module, function_name) def example4(): print(repr(getfunctionbyname("dumbdbm","open"))) #example 5 class LazyImport: def __init__(self, module_name): self.module_name = module_name self.module = None def __getattr__(self, item): if self.module is None: self.module = __import__(self.module_name) return getattr(self.module, item) def example5(): string = LazyImport("string") print(string.lowercase) print(string.module_name) #example 6 def dump(value): print(value,"=>",dir(value)) def example6(): import sys dump(0) dump(1.0) dump(0.0j) dump([]) dump({}) dump("string") dump(len) dump(sys) #example 7 class A: def a(self): pass def b(self): pass class B(A): def c(self): pass def d(self): pass def getmembers(kclass, members=None): #get a list of all class members, ordered by class if members is None: members=[] for k in kclass.__bases__: getmembers(k, members) for m in dir(kclass): if m not in members: members.append(m) return members def example7(): print(getmembers(A)) print(getmembers(B)) print(getmembers(IOError)) #example 8 def example8(): book = "library2" pages = 250 scripts = 350 print("the %(book)s book contains more than %(scripts)s scripts" % vars()) #example 9 def example9(): def dump(value): print(type(value),value) dump(1) dump(1.0) dump("one") #example 10 def example10(): def load(file): if isinstance(file, type("")): file = open(file, "rb") return file.read() print(len(load("./__builtin__.py")),"bytes") #print(len(load(open("./main.py","rb"))),"bytes") #example 11 def example11(): def dump(function): if callable(function): print(function, "is callable") else: print(function, "is not callable") class A: def method(self,value): return value class B(A): def __call__(self,value): return value a = A() b = B() dump(0) #simple object dump("string") dump(callable) dump(dump) dump(A) dump(B) dump(B.method) dump(a) dump(b) dump(b.method) #example 12 def example12(): class A: pass class B: pass class C(A): pass class D(A, B): pass def dump(object): print(object,"=>",) if isinstance(object, A): print("A") if isinstance(object, B): print("B") if isinstance(object, C): print("C") if isinstance(object, D): print("D") a = A() b = B() c = C() d = D() dump(a) dump(b) dump(c) dump(d) dump(0) dump("string") #example 13 def example13(): class A: pass class B: pass class C(A): pass class D(A, B): pass def dump(object): print(object,"=>") if issubclass(object, A): print("A") if issubclass(object, B): print("B") if issubclass(object, C): print("C") if issubclass(object, D): print("D") dump(A) dump(B) dump(C) dump(D) #dump(0) #dump("string") #example 14 def example14(): def dump(expression): result = eval(expression) print(expression, "=>", result, type(result)) dump("1") dump("1.0") dump("'string'") dump("1.0+2.0") dump("'*'*10") dump("len('world')") #example 15 def example15(): BODY = """print('the ant, an introduction')""" code = compile(BODY, "<script>","exec") print(locals()) print(code) exec(code) #example 16 #import sys,string import string class CodeGeneratorBackend: "Simple code generator for Python" def begin(self, tab ="\t"): self.code = [] self.tab = tab self.level = 0 def end(self): self.code.append("")#make sure there's a newline at the end return compile(string.join(self.code,"\n"),"<code>","exec") def write(self,string): self.code.append(self.tab * self.level + string) def indent(self): self.level = self.level + 1 def dedent(self): if self.level == 0: raise SystemError,"internal error in code generator" self.level = self.level -1 def example16(): c = CodeGeneratorBackend() c.begin() c.write("for i in range(5):") c.indent() c.write("print('code generation made easy!')") c.dedent() exec(c.end()) #example 17 def example17(): def open(filename, mode="rb"): import __builtin__ file = __builtin__.open(filename, mode) if file.read(5) not in ("GIF87", "GIF89"): print("hello world") raise IOError, "not a GIF file" file.seek(0) return file fp = open("__builtin__.py") print(len(fp.read()),"bytes") #example 18 class HTTPError(Exception): def __init__(self, url, errcode, errmsg): self.url = url self.errcode = errcode self.errmsg = errmsg def __str__(self): return ("<HTTPError for %s :%s %s> % (self.url, self.errcode, self.errmsg))") def example18(): try: raise HTTPError("http://www.python.org/foo", 200, "Not Found") except HTTPError, error: print("url =>",error.url) print("errcode =>",error.errcode) print("errmsg =>", error.errmsg) #example 19 def example19(): import os , string def replace(file, search_for, replace_with): back = os.path.splitext(file)[0] + ".bak" temp = os.path.splitext(file)[0] + ".tmp" try: os.remove(temp) except os.error: pass fi = open(file) fo = open(temp, "w") for s in fi.readlines(): fo.write(string.replace(s, search_for, replace_with)) fi.close() fo.close() try: os.remove(back) except os.error: pass os.rename(file, back) os.rename(temp, file) print("replace string .") #example 20 def example20(): import os cwd = os.getcwd() print(repr(cwd)) for file in os.listdir(cwd): print(file) pass path = "C:\\" os.chdir(path) print(os.getcwd()) for file in os.listdir(path): print(file) #example 21 def example21(): import os ,time currentPath = os.getcwd() print(currentPath) file = currentPath +"/__builtin__.py" print("file is %s" % file) def dump(st): mode, ino, dev, nlink, uid, gid, size, atime, mtime, ctime = st print("-size: %s bytes" % size) print("-owner: %s %s" % (uid, gid)) print("-owner_s: %(hh)s %(uu)s" % {"hh":uid, "uu":gid}) print("-created:", time.ctime(ctime)) print("-last accessed:", time.ctime(atime)) print("-last modified:", time.ctime(mtime)) print("-mode:", oct(mode)) print("-inode/dev:", ino,dev) st = os.stat(file) print("stat") print(st) dump(st) #example 22 def example22(): import os if os.name == "nt": command = "dir" else: command = "ls -l" os.system(command) #example 23 def example23(): import os, sys program = "python" currentPath = os.getcwd() arguments = ["%s/main.py" % currentPath] print(arguments) result =os.execvp(program, (program,) + tuple(arguments)) print(result) print("goodbye") #example 24 without windows system! #only for unix def example24(): import os, sys currentPath = os.getcwd() scriptPath = "%s/main.py" % currentPath def run(program, *args): pid = os.fork() if not pid: os.execvp(program, (program,) + args) return os.wait()[0] run("python",scriptPath) print("goodbye") #example 25 #only for linux import os, string def run(program, *args): #find executable for path in string.split(os.environ["path"], os.pathsep): print(path) file = os.path.join(path, program) + ".exe" try: if os.path.exists(file): return os.spawnv(os.P_WAIT, file, (file,)+args) else: raise os.error ,"the path is not exist" except os.error,e: print(e) pass raise os.error, "cannot find exectuable" def example25(): run("python", "main.py") #example 26 #only for windows def example26(): import os, string def run(program, *args, **kw): mode = kw.get("mode", os.P_WAIT) for path in string.split(os.environ["path"], os.pathsep): file = os.path.join(path, program)+".exe" try: return os.spawnv(mode, file, (file,)+args) except os.error: pass raise os.error, "cannot find excutable" #exmaple 27 def example27(): import os, string if os.name in ("nt", "dos"): exefile = ".exe" print("this os is windows or dos") else: exefile = "" def spawn(program, *args): try: return os.spawnvp(program, (program,)+args) except AttributeError: pass try: spawnv = os.spawnv except AttributeError: #assume it's unix pid = os.fork() if not pid: os.execvp(program, (program,)+args) return os.wait()[0] else: #got sapwnv but no sapwnp: to look for an executable for path in string.split(os.environ["PATH"], os.pathsep): file = os.path.join(path, program) + exefile if os.path.exists(file): print("the file is %s" % file) try: return spawnv(os.P_WAIT, file , (file,)+args) except os.error: pass else: print("the file is no exist.") raise IOError, "cannot find executable" spawn("python", "main.py") #example 28 #only for unix def example28(): #daemon processes import os, time pid = os.fork() if pid: os._exit(0) #kill original print("daemon started") time.sleep(10) print("daemon terminated") #example 29 def example29(): import os, sys try: sys.exit(1) except SystemExit, value: print("caught exit(%s)" % value) try: print("try excute the code.") os._exit(2) except SystemExit, value: print("caught exit(%s)" % value) print("bye!") #example 30 def example30(): import os filename = "my/little/pony.txt" #filename = "my/little/pony" print("the filename:%s" % filename) print("using %s ... " % os.name) print("split =>", os.path.split(filename)) print("splitext =>", os.path.splitext(filename)) print("dirname =>", os.path.dirname(filename)) print("basename =>", os.path.basename(filename)) print("join =",os.path.join(os.path.dirname(filename), os.path.basename(filename))) #example 31 def example31(): import os FILES = (os.curdir, "/", "file", "/file", "samples", "samples/sample.jpg", "directory/file", "../directory/file", "/directory/file" ) for file in FILES: print(file,"=>") if os.path.exists(file): print("EXISTS") if os.path.isabs(file): print("ISABS") if os.path.isdir(file): print("ISDIR") if os.path.isfile(file): print("ISFILE") if os.path.islink(file): print("ISLINK") if os.path.ismount(file): print("ISMOUNT") print("######end######") #exmaple 32 def example32(): import os print(os.path.expanduser("~/.pythonrc")) #example 33 def example33(): import os for i in os.environ: print(i) os.environ["USER"] = "user" print(os.path.expandvars("/home/$USER/config")) print(os.path.expandvars("/$USER/folders")) #example 34 def example34(): import os def callback(arg, directory, files): print("#######") print(directory,"the files number is %d" % len(files)) for file in files: print(os.path.join(directory, file), repr(arg)) os.path.walk(".", callback, "secret message") #example 35 def example35(): import os def index(directory): # like os.listdir, but traverses directory trees stack = [directory] files = [] while stack: directory = stack.pop() for file in os.listdir(directory): fullname = os.path.join(directory, file) files.append(fullname) if os.path.isdir(fullname) and not os.path.islink(fullname): stack.append(fullname) return files for file in index("."): print(file) #example 36 def example36(): import os class DirectoryWalker: # a forward iterator that traverses a directory tree def __init__(self, directory): self.stack = [directory] self.files = [] self.index = 0 def __getitem__(self, index): while 1: try: file = self.files[self.index] self.index = self.index + 1 except IndexError: # pop next directory from stack self.directory = self.stack.pop() self.files = os.listdir(self.directory) self.index = 0 else: # got a filename fullname = os.path.join(self.directory, file) if os.path.isdir(fullname) and not os.path.islink(fullname): self.stack.append(fullname) return fullname for file in DirectoryWalker("."): print(file) #example 37 def example37(): import os , stat class DirectoryStatWalker: def __init__(self, directory): self.stack = [directory] self.files = [] self.index = 0 def __getitem__(self, index): while 1: try: file = self.files[self.index] self.index = self.index + 1 except IndexError: self.directory = self.stack.pop() self.files = os.listdir(self.directory) self.index = 0 else: fullname = os.path.join(self.directory, file) st = os.stat(fullname) mode = st[stat.ST_MODE] if stat.S_ISDIR(mode) and not stat.S_ISLNK(mode): self.stack.append(fullname) return fullname,st for file, st in DirectoryStatWalker("."): print(file, st[stat.ST_SIZE]) #example 38 def example38(): import stat import os, time st = os.stat("./main.py") print("mode => ", oct(stat.S_IMODE(st[stat.ST_MODE]))) print("type => ") if stat.S_ISDIR(st[stat.ST_MODE]): print("DIRECTORY") if stat.S_ISREG(st[stat.ST_MODE]): print("REGULAR") if stat.S_ISLNK(st[stat.ST_MODE]): print("LINK") pass print("size => ", st[stat.ST_SIZE]) print("last accessed => ", time.ctime(st[stat.ST_ATIME])) print("last modified => ", time.ctime(st[stat.ST_MTIME])) print("inode changed => ", time.ctime(st[stat.ST_CTIME])) #example 39 def example39(): import string text = "Monty Python's Flying Circus" print("upper => %s" % string.upper(text)) print("lower => %s" % string.lower(text)) print("split => %s" % string.split(text)) print("join => %s" % string.join(text, '+')) print("replace => %s" % string.replace(text, "Python", "Java")) print("find => ", string.find(text, "Python"), string.find(text, "Java")) print("count => ", string.count(text, 'n')) #example 40 def example40(): text = "Monty Python's Flying Circus" print("upper => %s" % text.upper()) print("lower => %s" % text.lower()) print("split => %s" % text.split()) print("join => %s" % text.join('+')) print("replace => %s" % text.replace("Python", "Java")) print("find => ", text.find("Python"), text.find("Java")) print("count => ", text.count('n')) #example 41 def example41(): import string print(int("4711")) print(string.atoi("4711")) print(string.atoi("11147", 8)) #octal print(string.atoi("1267", 16)) #hexadecimal print(string.atoi("3mv", 36)) #whatever... print(string.atoi("4711", 0)) print(string.atoi("04711", 0)) print(string.atoi("0x4711", 0)) print float("4711") print(string.atof("1")) print(string.atof("1.23e5")) #example 42 def example42(): import re text = "the Attila the Hun Show" # a single character m = re.match(".", text) if m: print(repr("."), "=>", repr(m.group(0))) #any string fo characters m = re.match(".*", text) if m: print(repr(".*"), "=>", repr(m.group(0))) #a string of letters (at least one) m = re.match("\w+", text) if m: print(repr("\w+"), "=>", repr(m.group(0))) # a string of digits m = re.match("\d+", text) if m: print(repr("\d+"), "=>", repr(m.group(0))) #example 43 def example43(): import re text = "10/15/99" m = re.match("(\d{2})/(\d{2})/(\d{2,4})", text) if m: print(m.group(1, 2, 3)) print(m.group()) print(m.group(1)) print(len(m.group())) #example 44 def example44(): import re text = "Example 3: There is 1 date 10/25/95 in here!" m = re.search("(\d{1,2})/(\d{1,2})/(\d{2,4})", text) print(m.group(1), m.group(2), m.group(3), "group") month, day, year = m.group(1, 2, 3) print(month, day, year) date = m.group(0) print(date) #example 45 def example45(): import re text = "you're no fun anymore..." #literal replace (string.replace is faster) print(re.sub("fun", "entertaining", text)) #collapse all non-letter sequences to a single dash print(re.sub("[^\w]+", "-", text)) #convert all words to beeps print(re.sub("\S+", "-BEEP-", text)) #example 46 def example46(): import re, string text = "a line of text\\012another line of text\\012etc..." def octal(match): #replace octal code with corresponding ASCII character return chr(string.atoi(match.group(1), 8)) octal_pattern = re.compile(r"\\(\d\d\d)") print(text) print octal_pattern.sub(octal, text) #example 47 def example47(): import re, string def combined_pattern(patterns): p = re.compile(string.join(map(lambda x: "("+x+")", patterns), "|")) def fixup(v, m = p.match, r = range(0, len(patterns))): try: regs = m(v).regs #print(regs) except AttributeError: return None # no match, so m.regs will fail else: for i in r: if regs[i+1] != (-1, -1): return i return fixup patterns = [r"\d+", r"abc\d{2,4}", r"p\w+" ] p = combined_pattern(patterns) print(p("129391")) print(p("abc800")) print(p("abc1600")) print(p("python")) print(p("perl")) print(p("tcl")) #example 48 def example48(): import math print("e => ", math.e) print("pi => ", math.pi) print("hypot => ", math.hypot(3.0, 4.0)) #example 49 def example49(): import cmath print("pi => ", cmath.pi) print("sqrt(-1) => ", cmath.sqrt(-1)) #example 50 def example50(): import operator sequence = 1, 2, 4 print("add => ", reduce(operator.add, sequence)) print("sub =>", reduce(operator.sub, sequence)) print("mul =>", reduce(operator.mul, sequence)) print("concat =>", operator.concat("spam", "egg")) print("repeat =>", operator.repeat("spam", 5)) print("getitem =>", operator.getitem(sequence, 2)) print("indexOf =>", operator.indexOf(sequence, 2)) print("sequenceIncludes =>", operator.sequenceIncludes(sequence, 3)) #example 51 def example51(): import operator, UserList def dump(data): print(type(data), "=>") if operator.isCallable(data): print("CALLABLE") if operator.isMappingType(data): print("MAPPING") if operator.isNumberType(data): print("NUMBER") if operator.isSequenceType(data): print("SEQUENCE") print("---") dump(0) dump("string") dump("string"[0]) dump([1, 2, 3]) dump((1, 2, 3)) dump({"a": 1}) dump(len) dump(UserList) dump(UserList.UserList) dump(UserList.UserList()) #example 52 def example52(): import copy a = [[1], [2], [3]] b = copy.copy(a) print("before a=>", a) print("before b=>", b) if a is b: print("a is b") else: print("a is not b") #modify original a[0][0] = 0 a[1] = None if a[0][0] is b[0][0]: print("a[0][0] is b[0][0]") else: print("a[0][0] is not b[0][0]") print("after a=>", a) print("after b=>", b) #example 53: def example53(): import copy a = [[1], [2], [3]] b = copy.deepcopy(a) print("before a=>", a) print("before b=>", b) if a is b: print("a is b") else: print("a is not b") # modify original a[0][0] = 0 a[1] = None if a[0][0] is b[0][0]: print("a[0][0] is b[0][0]") else: print("a[0][0] is not b[0][0]") print("after a=>", a) print("after b=>", b) #example 54: def example54(): import sys print("script name is: ", sys.argv[0]) if len(sys.argv) > 1: print("there are ", len(sys.argv) - 1, "arguments:") for arg in sys.argv[1:]: print(arg) else: print("there are no arguments!") #example 55: def example55(): import sys print("path has", len(sys.path), "members") #add the sample directory to the path sys.path.insert(0, "samples") import sample sys.path = [] import random #example 56: def example56(): import sys def dump(module): print("module => ") if module in sys.builtin_module_names: print("<BUILTIN>") else: module = __import__(module) print(module.__file__) dump("os") dump("sys") dump("string") dump("strop") dump("zlib") #example 57: def example57(): import sys, pprint moduleKeys = sys.modules.keys() print(len(moduleKeys)) print(moduleKeys) pprint.pprint(moduleKeys) #example 58: def example58(): import sys variable = 1234 print(sys.getrefcount(0)) print(sys.getrefcount(variable)) print(sys.getrefcount(None)) #example 59: def example59(): import sys if sys.platform == "win32": import ntpath pathmodule = ntpath elif sys.platform == "mac": import macpath pathmodule = macpath else: import posixpath pathmodule = posixpath print(pathmodule) #example 60 def example60(): import sys def test(n): j = 0 for i in range(n): j = j + 1 return n def profiler(frame, event, arg): print(event, frame.f_code.co_name, frame.f_lineno, "->", arg) sys.setprofile(profiler) test(1) sys.setprofile(None) test(2) #example 61: def example61(): import sys def test(n): j = 0 for i in range(n): j = j + i return n def tracer(frame, event, arg): print(event, frame.f_code.co_name, frame.f_lineno, "->", arg) return tracer sys.settrace(tracer) test(1) sys.settrace(None) test(2) #example 62: def example62(): import sys, string class Redirect: def __init__(self, stdout): self.stdout = stdout def write(self, s): self.stdout.write(string.lower(s)) old_stdout = sys.stdout sys.stdout = Redirect(sys.stdout) print("HEJA SVERIGE") print("FRISKT HUM\303\226R") sys.stdout = old_stdout print("M\303\205\303\205\303\205\303\205L!") #example 63: def example63(): import sys print("hello") sys.exit(1) print("there") #example 64: def example64(): import sys print("hello") try: sys.exit(1) except SystemExit, e: pass print("get the except:SystemExit %s" % e) print("there") #example 65: def example65(): import sys def exitfunc(): print("world") sys.exitfunc = exitfunc print("hello ") sys.exit(1) print("there") #example 66: def example66(): import atexit def exit(*args): print("exit", args) #register two exit handler atexit.register(exit) atexit.register(exit, 1) atexit.register(exit, "hello", "world", "!") #example 67: def example67(): import time now = time.time() print(now, "Seconds since ", time.gmtime(0)[:6]) print("-local time:", time.localtime(now)) print("-utc:", time.gmtime(now)) #example 68: def example68(): import time now = time.localtime(time.time()) print(time.asctime(now)) print(time.strftime("%y/%m/%d %H:%M", now)) print(time.strftime("%c", now)) print(time.strftime("%I %p", now)) print(time.strftime("%Y-%m-%d %H:%M:%S %Z", now)) year, month, day, hour, minute, second, weekday, yearday, daylight = now print("%04d-%02d-%02d" % (year, month, day)) print("%02d:%02d:02%d" % (hour, minute, second)) print(("MON", "TUE", "WED", "THU", "FRI", "SAT", "SUN")[weekday], yearday) #example 69 def example69(): import time try: strptime = time.strptime except AttributeError: print("exception about the function: strptime") from _strptime import strptime print(strptime("31 Nov 00"), "%d %b %y") #example 70 def example70(): import time t0 = time.time() tm = time.localtime(t0) print(tm) print(t0) print(time.mktime(tm)) #example 71 def example71(): import time def procedure(): time.sleep(2.5) #measure process time t0 = time.clock() procedure() print(time.clock() - t0, "Seconds process time") #measure wall time t0 = time.time() procedure() print(time.time() - t0, "Seconds wall time") if __name__ == "__main__": print("process %s section start" % "__builtin__") print("---") boolWhichWay = True if boolWhichWay: for i in xrange(1, 1000): strFunctionName = "example%d" % i if strFunctionName in globals(): pass else: strFunctionName = "example%d" % (i-1) strExcuteFunctionName = "%s()" % strFunctionName print("#excute function %s:" % strFunctionName) eval(str(strExcuteFunctionName), globals()) print("---") break else: for i in xrange(1, 1000): strFunctionName = "example%d" % i if strFunctionName in globals(): strFunctionName = "example%d" % i strExcuteFunctionName = "%s()" % strFunctionName print("#excute function %s:" % strFunctionName) eval(str(strExcuteFunctionName), globals()) print("---") else: break print("process end")