knights = {'gallahad': 'the pure', 'robin': 'the brave'}
	for k, v in knights.items():
		print(k, v)
	
	
	gallahad the pure
	robin the brave

for i, v in enumerate(['tic', 'tac', 'toe']):
    print(i, v)


0 tic
1 tac
2 toe

data1 = [1,2,3,4,5]
data2 = [2,2,2,2,2]
# zip函数获得迭代器，只能遍历一次

# 1. 将多个列表压缩到一起， [(1, 2), (2, 2), (3, 2), (4, 2), (5, 2)]
dd = zip(data1, data2);

data = list(dd)
print(data)

# 2. 进行拆分， *号表示对参数进行拆分
a, b = zip(*data)
print(a, b)# (1, 2, 3, 4, 5) (2, 2, 2, 2, 2)

arr = [9,1,3,5,2]
map = {
	i : arr[i] * i
	for i in range(0, len(arr))
}
print(map) # {0: 0, 1: 1, 2: 6, 3: 15, 4: 8}

使用内置函数sorted,对复杂结构进行排序

map = {0: 0, 1: 1, 2: 6, 3: 15, 4: 8}

map = sorted(map.items(), 		# 要排序的集合
   key = lambda  data : data[1],# 指定要排序的key
   reverse = True)				# True降序排序
   
print(map) # [(3, 15), (4, 8), (2, 6), (1, 1), (0, 0)]

from collections import defaultdict

dir = defaultdict(int)# int
dir['key1']
print(dir)

dir = defaultdict(list) # 列表
dir['key1'].append("value1")
dir['key1'].append("value2")
print(dir)

dir = defaultdict(dict) # 字典
dir['key1']['key1_1'] = 11
print(dir)

dir = defaultdict(float) #小数
dir['key1']
print(dir)

dir = defaultdict(str)# 字符串
dir['key1']
print(dir)

dir = defaultdict(bool)# 布尔
dir['key1']
print(dir)

dir = defaultdict(lambda:[0, 0, 0])# 自定义初始化的值
dir['key1']
print(dir)

from collections import Counter

data = {'k1': 1, 'k2': 1, 'k3': 1, 'k4': 2, 'k5': 2 }
	
c = Counter([ kv[1] for kv in data.items() ])
# 全部的统计结果
print(c)# Counter({1: 3, 2: 2})
# 数量最大的一个
print(c.most_common(1))

def func (*args, **kwargs) :
    print("未命名:args=", args)
    print("已命名:kwargs=", kwargs)

func(1,2, key=1)

未命名:args= (1, 2)
已命名:kwargs= {'key': 1}

def func2 (*args, **kwargs) :
    key = 'f1'# 输入一个函数
    f1 = kwargs.get(key)
    return f1(args[0])

# 定义一个求和函数
def demo(args):
    return sum(args)

data = [1, 2, 3, 4]
print(demo(data))
print(func2(data, f1=demo))

print(help(len))

返回以下结果
Help on built-in function len in module builtins:

len(obj, /)
    Return the number of items in a container.

None