【python--字典】 dict 创建 的8种方法

# 字典 #{}
dic = {} print(dic) print(type(dic))   # <class 'dict'>

# 语法格式 {'xuann':2,'lic':65} # key --- 键 # value --- 值 # 键值对 一个元素

# 1:创建字典
d1 = dict() print(d1)       # 空字典 {}

# 2:通过直接赋值创建
di = {'sop':2,'kai':5} print(di)      # {'sop': 2, 'kai': 5}

# 3:通过dict函数和关键字创建
die = dict(snian = 1,ajija = 6,) print(die)     # {'snian': 1, 'ajija': 6}

# 4:通过二元组创建 通过列表转字典
die =[(15,3),('nijao',3)] di = dict(die) print(di)      # {15: 3, 'nijao': 3}

# 5:zip函数
re = zip([1,2,3,6,5,9])     # zip 后 为可迭代对象
print(re)                     # <zip object at 0x013FF1A8> 迭代器
for i in re:                  # 迭代循环
    print(i) # (1,)
    # (2,)
    # (3,)
    # (6,)
    # (5,)
    # (9,)
re = zip([1,2,3,4],[11,22,33,44]) for i in re: print(i) # (1, 11) # (2, 22) # (3, 33) # (4, 44)
re = zip('nihao',[1,2,3,4,5,]) for i in re : print(i) # ('n', 1) # ('i', 2) # ('h', 3) # ('a', 4) # ('o', 5)

# print(re.__next__()) # (1,) # 先用zip函数迭代出元组形式的元素 取出 放到字典里
de = dict(zip('mijao',[1,2,35,4,8])) print(de) # {'m': 1, 'i': 2, 'j': 35, 'a': 4, 'o': 8}

# 6:通过字典的推导式 创建 # lis = [i*2 for i in range] list 推导式
dic = {str(i) : i*2  for i in range(9)}  #dict 推导式
print(dic) #{'0': 0, '1': 2, '2': 4, '3': 6, '4': 8, '5': 10, '6': 12, '7': 14, '8': 16}

# 7:用 dict.fromkeys #通常用来初始化字典，设置value的默认值
di = dict.fromkeys('nihao',3)          # {k:value,k:value,k:value,........}
print(di) # {'n': 3, 'i': 3, 'h': 3, 'a': 3, 'o': 3}

# 8: 其他方式
l = ['x',1,'y',2,'o',5] de = dict(zip(l[::2],l[1::2])) print(de) # {'x': 1, 'y': 2, 'o': 5