弹簧腿杰克-杰克逊,超越梦想简谱,天师执位小说
目录
print([abd(i) for i in lst])
[(0,1),(1,2),(2,3)] print([i for i in enumerate(lst,10)]) lst = [11,22,33,-44,23,21] new_lst = [] for i in enumerate(lst): new_lst.append(i) print(new_lst) print([i for i in enumerate(lst,1000)])
print(max([1,2,3,4,56,7,8]))
print(min([1,2,3,4,-56,7,8]))
print(sum([1,2,3,4,5],100))
python3.6: g = range(0,10) # 可迭代对象 g.__iter__() python2.6: range(0,10) # 获取是一个列表 xrange(0,10) # 获取是一个可迭代对象 from collections import iterable,iterator print(isinstance(g,iterable)) print(isinstance(g,iterator))
print(sep=" ", end="\n") print(1, 2, 3, sep=" ") # sep多个元素的连接符 print(1, end="\t") print(2, end=" ") print(3)
print(12345,file=open("t1.txt","w",encoding="utf-8"))
print(list("alex")) #['alex',] print(dict(key=1,a="alex")) print(dict(((1,2),(2,3),(3,4)))) print(dict([i for i in enumerate(range(20),1)]))
lst1 = [1,2,3,4,5] lst2 = ['a',"b","c","d","f","e"] print(dict(list(zip(lst1,lst2)))) # 面试题 print(dict(zip(lst1,lst2))) # 面试题
print(dir(list))
f = lambda x,y:(x,y) print(f(1,2)) print(f.__name__) def func(): return 1 print(func()) print((lambda x:x)(2)) # 同一行定义 同一行调用 lambda 关键字 -- 定义函数 x,y 形参 :x+y 返回值 -- 只能返回一个数据类型 lst = [lambda i:i*i for i in range(10)] print(lst[2](2)) lst = [] for i in range(10): def func(i): return i*i lst.append(func) print(lst[2](3)) lst = [lambda :i*i for i in range(10)] print(lst[2]()) for i in range(10): pass print(i) lst = [] for i in range(10): def func(): return i*i lst.append(func) print(lst[2]()) 一行函数 形参可以不写 返回值必须要写,返回值只能返回一个数据类型 lst = list((lambda i:i*i for i in range(5))) print(lst[1](4)) lst = [x for x in (lambda :i**i for i in range(5))] print(lst[2]()) lst1 = [] def func(): for i in range(5): def foo(): return i**i yield foo for x in func(): lst1.append(x) print(lst1[2]())
print(format(13,">20")) # 右对齐 print(format(13,"<20")) # 左对齐 print(format(13,"^20")) # 居中 # 进制转换 print(format(13,"08b")) # 2 print(format(13,"08d")) # 10 print(format(13,"08o")) # 8 print(format(12,"08x")) # 16 print(bin(13))
lst = [1,2,3,4,5,6,7] def func(s): return s > 3 print(list(filter(func,lst))) # func就是自己定义一个过滤条件,lst要迭代的对象 lst = [1,2,3,4,5,6,7] print(list(filter(lambda x:x % 2 == 1,lst)))
print(list(map(lambda x:x*x,[1,2,3,8,4,5]))) 对可迭代对象中每个元素进行加工
lst = [1,2,3,4,5] lst.reverse() print(lst) lst1 = list(reversed(lst)) print(lst) print(lst1)
lst = [1,23,34,4,5,213,123,41,12,32,1] print(sorted(lst)) # 升序 print(lst) lst = [1,23,34,4,5,213,123,41,12,32,1] print(sorted(lst,reverse=true)) # 降序
dic = {"key":1,"key1":2,"key3":56} print(sorted(dic,key=lambda x:dic[x],reverse=true)) # key是指定排序规则 print(max([1,2,-33,4,5],key=abs)) # key指定查找最大值的规则
from functools import reduce # reduce 累计算 print(reduce(lambda x,y:x-y,[1,2,3,4,5])
def func(): a = 1 def f1(): def foo(): print(a) return foo return f1 ret = func() a = ret() a() func()()()
avg_lst = [] def func(pirce): avg_lst.append(pirce) avg = sum(avg_lst) / len(avg_lst) return avg print(func(150000)) print(func(160000)) print(func(170000)) print(func(150000)) avg_lst.append(18888888)
def func(pirce): avg_lst = [] avg_lst.append(pirce) avg = sum(avg_lst) / len(avg_lst) return avg print(func(150000)) print(func(160000)) print(func(170000)) print(func(150000))
def func(): avg_lst = [] # 自由变量 def foo(pirce): avg_lst.append(pirce) avg = sum(avg_lst) / len(avg_lst) return avg return foo ret = func()()
print(ret(150000)) print(ret(160000)) print(ret(170000)) print(ret(150000)) print(ret(180000)) print(ret.__closure__) (<cell at 0x0000018e93148588: list object at 0x0000018e931d9b08>,)
了解: print(ret.__code__.co_freevars) # 获取的是自由变量 print(ret.__code__.co_varnames) # 获取的是局部变量
1. 保证数据的安全性 2. 装饰器
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