python中dict获取关键字与值的实现
时间：2022-07-24 10:16:05 | 栏目：Python代码 | 点击：次
dict获取关键字与值
values()
>>> d
{'p': 34, 'l': 54, 'b': 88}
>>> for value in d.values():
... print(value)
...
34
54
88
items()
>>> for key,value in d.items(): ... print(key,value) ... p 34 l 54 b 88
字典dict(关键字对应的值为list)
方法一
代码
# method 1
pages = {}
page = []
for img_name in os.listdir(args.image_dir):
pre_str = img_name[:2]
#print(pre_str)
if pre_str not in pages.keys():
tmp_list = []
tmp_list.append(os.path.join(args.image_dir, img_name))
pages[pre_str] = tmp_list
else:
pages[pre_str].append(os.path.join(args.image_dir, img_name))
print(pages)
输出
方法二
代码
# method 2
from collections import defaultdict
pages = defaultdict(list)
for img_name in os.listdir(args.image_dir):
pre_str = img_name[:2]
#print(pre_str)
pages[pre_str].append(os.path.join(args.image_dir, img_name))
print(list(pages.items()))
print(pages)
输出 print(list(pages.items()))的输出
print(pages)的输出
