Python 枚舉還是別的什么？

Question

我從遵循此示例的 json object 開始：

[
  {
    "url": "https://www.stackoverflow_greatquestions.com",
    "pages": 1
  },
  {
    "url": "https://www.stackoverflow_not-so-greatquestions.com",
    "pages": 3
  }
]

我想要完成的是打印等於我這樣做的頁數的 url：

url_list = []
for x in json:
    for y in range(x['pages']):
        url_list.append(x['url'])

我快到了，這是按照我的要求打印出網址，但我還想根據頁面的值對 output 進行編號。

所以我的最終結果是這樣的：

"https://www.stackoverflow_greatquestions.com", 1,
"https://www.stackoverflow_not-so-greatquestions.com", 1,
"https://www.stackoverflow_not-so-greatquestions.com", 2,
"https://www.stackoverflow_not-so-greatquestions.com", 3

我覺得 enumerate 在這里會很有用，但我似乎無法理解如何實現它。 我所能做的就是給整個列表編號，正如你從上面看到的那樣，這不是我想要完成的。

提前謝謝你，布賴恩

Answer 1

這是一種方法。 沒什么特別的，只是一個for循環和一個依賴於'pages'鍵的range 。

>>> data = [ 
...:   { 
...:     "url": "https://www.stackoverflow_greatquestions.com", 
...:     "pages": 1 
...:   }, 
...:   { 
...:     "url": "https://www.stackoverflow_not-so-greatquestions.com", 
...:     "pages": 3 
...:   } 
...: ]                                                                                                                        
>>>                                                                                                                           
>>> for d in data: 
...:     for i in range(1, d['pages'] + 1): 
...:         print(d['url'], i) 
...:                                                                                                                          
https://www.stackoverflow_greatquestions.com 1
https://www.stackoverflow_not-so-greatquestions.com 1
https://www.stackoverflow_not-so-greatquestions.com 2
https://www.stackoverflow_not-so-greatquestions.com 3

編輯 - 建立一個列表：

>>> result = [(d['url'], i) for d in data for i in range(1, d['pages'] + 1)]                                                  
>>> result                                                                                                                    
[('https://www.stackoverflow_greatquestions.com', 1),
 ('https://www.stackoverflow_not-so-greatquestions.com', 1),
 ('https://www.stackoverflow_not-so-greatquestions.com', 2),
 ('https://www.stackoverflow_not-so-greatquestions.com', 3)]

Answer 2

這將正常工作：

url_list = []
for x in json:
    for y in range(x['pages']):
        url_list.append(x['url']+', '+str(y+1))
print(url_list)

Output

['https://www.stackoverflow_greatquestions.com, 1', 'https://www.stackoverflow_not-so-greatquestions.com, 1', 'https://www.stackoverflow_not-so-greatquestions.com, 2', 'https://www.stackoverflow_not-so-greatquestions.com, 3']