Python基础学习代码之函数和函数式编程
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2022-05-16 21:45:51
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def func1(): print 'hello world' res = func1() print type(res) def func2(): return ['xyz',10000,-98] atuple = func2() x,y,z = func2() print x,y,z def func3(): return 'xyz',1000,-98 x,y,z = func3() print x,y,z def func4(): return ['xyz',1000,-98,'xxx'] x,y,z,d = func4() alist = x,y,z,d print alist true = lambda :True print true() sum = lambda x,y:x + y summ = lambda x,y=4:x + y atuplet = lambda *zaz:zaz print atuplet('a',1) adictt = lambda **z:z print adictt(x=3,y=5) from random import randint def functest(arg): return arg % 2 allnums = [] for eachnum in range(9): allnums.append(eachnum) print filter(functest,allnums) allnums = [] for eachnum in range(9): # print eachnum ra = randint(1,99) # print ra allnums.append(ra) #print filter(lambda x:x%2,allnums) #print [i for i in allnums if i%2] print [n for n in [randint(1,99) for i in range(9)] if n%2] print map(lambda x:x+2,[i for i in range(9)]) print map(lambda x:x**2,[int(i) for i in range(9)]) print map(str,[i for i in range(9)]) print map(lambda x,y:x+y,[1,2,3],[1,2,3]) print map(lambda x,y:(x+y,x-y),[1,2,3],[1,2,3]) print map(None,[1,2,3],[1,2,3]) print reduce(lambda x,y:x+y,[i for i in range(3)]) from operator import mul,add from functools import partial add1 = partial(add,1) mul100 = partial(mul,100) basetwo = partial(int,base=2) basetwo.__doc__ = 'convert base 2 string to an int' print basetwo('10010') import Tkinter root = Tkinter.Tk() mybutton = partial(Tkinter.Button,root,fg='white',bg='blue') b1 = mybutton(text='button1') b2 = mybutton(text='button2') qb = mybutton(text='quit',bg='red',command=root.quit) b1.pack() b2.pack() qb.pack(fill=Tkinter.X,expand=True) root.title('pfas!') root.mainloop() is_this_global = 'xyz' def foo(): global is_this_global this_is_local = 'abc' is_this_global = 'def' print this_is_local + is_this_global def foor(): m = 3 def bar(): n = 4 print m + n print m bar() def counter(start=0): count = [start] def incr(): count[0] += 1 return count[0] return incr count = counter() output = '<int %r id=%#0x val=%d>' w = x = y = z = 1 def f1(): x = y = z = 2 def f2(): y = z = 3 def f3(): z = 4 print output%('w',id(w),w) print output%('x',id(x),x) print output%('y',id(y),y) print output%('z',id(z),z) clo = f3.func_closure if clo: print 'f3 closure vars:',[str(c) for c in clo] else: print 'no f3 closure vars' f3() clo = f2.func_closure if clo: print 'f2 closure vars:',[str(c) for c in clo] else: print 'no f2 closure vars' f2() clo = f1.func_closure if clo: print 'f1 closure vars:',[str(c) for c in clo] else: print 'no f1 closure vars' from time import time def logged(when): def log(f,*args,**kargs): print '''called: function:%s args:%s kargs:%s'''%(f,args,kargs) def pre_logged(f): def wrapper(*args,**kargs): log(f,*args,**kargs) return f(*args,**kargs) return wrapper def post_logged(f): def wrapper(*args,**kargs): now = time() try: return f(*args,**kargs) finally: log(f,*args,**kargs) print 'time delta:%s' % (time()-now) return wrapper try: return {'pre':pre_logged,'post':post_logged}[when] except KeyError,e: raise ValueError(e),"must be 'pre' or 'post'" @logged('post') def hello(name): print 'hello,',name hello('world!') x = 10 def ffoo(): y = 5 bar = lambda z:x+z print bar(y) j,k = 1,2 def proc1(): j,k = 3,4 print 'j==%d and k==%d' % (j,k) def proc2(): j = 6 proc1() print 'j==%d and k==%d' % (j,k) k = 7 proc1() print 'j==%d and k==%d' % (j,k) j = 8 proc2() print 'j==%d and k==%d' % (j,k) def max2(arg1,arg2): if arg1 > arg2: return arg1 elif arg1 == arg2: return 'equal' else: return arg2 max22 = lambda a,b:a if a > b else b min22 = lambda a,b:a if a < b else b def heji(a,b): return a+b,a*b x,y = heji(3,4) def mymin(a,b,*num): minnum = min22(a,b) for each in num: minnum = min22(minnum,each) return minnum def mymax(a,b,*num): maxnum = max22(a,b) for each in num: maxnum = max22(maxnum,each) return maxnum trantime = lambda m:(unicode(m / 60),unicode(m % 60)) print ':'.join(trantime(80)) a = ['jia','wo','ma'] b = ['get','hoa','?'] print map(None,a,b) print zip(a,b) def oddyear(y): if (y % 4 == 0 and y % 100 != 0) or y % 400 == 0: return y print filter(oddyear,range(1999,2030)) print [y for y in range(1999,2030) if (y % 4 == 0 and y % 100 != 0) or y % 400 == 0] print reduce(lambda x,y:x+y,range(6)) / float(6) cl = lambda x:x.strip() res = map(cl,open('e:\\thefile.txt')) import time def timeit(arg): starttime = time.clock() result = arg endtime = time.clock() return (result,endtime-starttime) def arg(a,b): return a * b print timeit(arg(3,4)) mult = lambda x,y:x * y print reduce(mult,range(9)[1:])
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