Python中dict排序的两种方法

d = {"a":1 , "b":3, "c":2}

""" 
	得到排好序的列表
	>>>d.items()  
	>>>dict_items([('a', 1), ('b', 3), ('c', 2)])
	
	reverse是排序规则是否反过来，默认是升序
	reverse = False 升序
	reverse = True 降序

	>>>d_list
	>>>[('a', 1), ('c', 2), ('b', 3)]  

	
"""
def get_sorted_list(d, reverse=False):
    return sorted(d.items(), key=lambda x:x[1], reverse=reverse)

d_list = get_sorted_list(d)

for key,val in d_list:
    print(key,val)
"""
out:
	a 1
	c 2
	b 3
"""

d = {"a":1 , "b":3, "c":2}
def sort_dict_by_keys(d, reverse=True):
	# 这里如果不强制转换会报错，因为d.keys()的类型是：<class 'dict_keys'>，没有sort方法
    keys = list(d.keys())
    keys.sort(reverse=reverse)
    return [(key,d[key]) for key in keys]

d_sort = sort_dict_by_keys(d)
print(d_sort)
"""
out:
	[('c', 2), ('b', 3), ('a', 1)]
"""

# 创建一个字典
dic={'a':'甘肃酒泉','b':'广州市','c':'四年'}
print(sorted(dic))

# 输出
['a', 'b', 'c']

print(sorted(dic.items(),key=lambda s:s[0]))
print(sorted(dic.items(),key=lambda s:s[1]))

# 输出
[('a', '甘肃酒泉'), ('b', '广州市'), ('c', '四年')]
[('c', '四年'), ('b', '广州市'), ('a', '甘肃酒泉')]