字典构造一般方法
a = dict(one=1, two=2, three=3)
print(a)
b = {'one': 1, 'two': 2, 'three': 3}
print(b)
c = dict(zip(['one', 'two', 'three'], [1, 2, 3]))
print(c)
d = dict([('one', 1), ('two', 2), ('three', 3)])
print(d)
e = dict({'one': 1, 'two': 2, 'three': 3})
print(e)
print(a == b == c == d == e)

字典推导式
dial_codes = [ # 以信息对为元素的列表
(86, 'China'),
(91, 'India'),
(1, 'United States'),
(62, 'Indonesia'),
(55, 'Brazil'),
(92, 'Pakistan'),
(880, 'Bangladesh'),
(234, 'Nigeria'),
(7, 'Russia'),
(81, 'Japan')
]
country_code = {country: code for code, country in dial_codes} # 以列表为数据载体,利用推导写入字典
print(country_code)
country_code1 = {code: country.upper() for country, code in country_code.items()
if code < 66} # 利用旧字典构建新字典,键值位置转换,国家改成大写,并仅输