使用 while 循环时如何将重复代码转换为函数

Question

我有一些极其重复的 Python 代码，我想将它们转换为一个函数，但我不确定其中的逻辑，因为它涉及到 while 循环。

#Get initial tracks for playlist and save to JSON file
tracks_file_count = 0
tracks_file_name = f'{str(tracks_file_count)}_tracks.json'
tracks_file = open(tracks_file_name,'w+')
tracks_response = requests.request('GET', 
  f'{config.global_url}/users/{user}/playlists/{playlist_id}/tracks',
  headers=headers
)
tracks_file.write(tracks_response.text)
tracks_file.close()
tracks_file = open(tracks_file_name,'r')
tracks = json.load(tracks_file)
#Save comma seperated track ID's to variable
id_dict = []
for i in tracks['items']:
    track_id = i['track']['id']
    id_dict.append(track_id)
id_comma = (','.join(id_dict))
#Get Audio Features
features_file_count = 0
features_file_name = f'{str(features_file_count)}_features.json'
features_file = open(features_file_name,'w+')
features_response = requests.request('GET', 
  f'{config.global_url}/audio-features/?ids={id_comma}', 
  headers=headers
)
features_file.write(features_response.text)
features_file.close()
features_file = open(features_file_name,'r')
features = json.load(features_file)
track_writer(tracks, playlist_id)
feature_writer(features, playlist_id)
next_url = tracks['next']



while next_url != None:
    tracks_file_count += 1
    tracks_file_name = f'{str(tracks_file_count)}_tracks.json'
    tracks_file = open(tracks_file_name,'w+')
    tracks_response = requests.request('GET', next_url, 
      headers=headers
    )
    tracks_file.write(tracks_response.text)
    tracks_file.close()
    tracks_file = open(tracks_file_name,'r')
    tracks = json.load(tracks_file)
    #Save comma seperated track ID's to variable
    id_dict = []
    for i in tracks['items']:
        track_id = i['track']['id']
        id_dict.append(track_id)
    id_comma = (','.join(id_dict))
    #Get Audio Features
    features_file_count += 1
    features_file_name = f'{str(features_file_count)}_features.json'
    features_file = open(features_file_name,'w+')
    features_response = requests.request('GET', 
      f'{config.global_url}/audio-features/?ids={id_comma}',
      headers=headers
    )
    features_file.write(features_response.text)
    features_file.close()
    features_file = open(features_file_name,'r')
    features = json.load(features_file)
    track_writer(tracks, playlist_id)
    feature_writer(features, playlist_id)
    next_url = tracks['next']    

链接到原始gist （编者注：缩进不是 100% 保留，换行）。

在我的例子中，我首先用 0_ 命名我的文件，然后当条件不等于“无”时，我再次执行代码，但增加文件名，使其以 1_ 开头，依此类推。 URL 也会发生变化。这个

表明唯一的变化是递增 1 和 URL。

Answer 1

只需将公共部分分解为一个函数即可：

def repetitiveStuff(tracks_file_count, next_url, features_file_count)
  tracks_file_name = f'{str(tracks_file_count)}_tracks.json'
  tracks_file = open(tracks_file_name,'w+')
  tracks_response = requests.request('GET', next_url, headers=headers)
  tracks_file.write(tracks_response.text)
  tracks_file.close()
  tracks_file = open(tracks_file_name,'r')
  tracks = json.load(tracks_file)
  #Save comma seperated track ID's to variable
  id_dict = []
  for i in tracks['items']:
    track_id = i['track']['id']
    id_dict.append(track_id)
  id_comma = (','.join(id_dict))
  #Get Audio Features
  features_file_name = f'{str(features_file_count)}_features.json'
  features_file = open(features_file_name,'w+')
  features_response = requests.request('GET', 
    f'{config.global_url}/audio-features/?ids={id_comma}', 
    headers=headers
  )
  features_file.write(features_response.text)
  features_file.close()
  features_file = open(features_file_name,'r')
  features = json.load(features_file)
  track_writer(tracks, playlist_id)
  feature_writer(features, playlist_id)
  return tracks['next']


#Get initial tracks for playlist and save to JSON file
next_url = repetitiveStuff(
  0,
  f'{config.global_url}/users/{user}/playlists/{playlist_id}/tracks',
  0
)

tracks_file_count = 0
features_file_count = 0

while next_url != None:
  tracks_file_count += 1
  features_file_count += 1
  next_url = repetitiveStuff(tracks_file_count, next_url, features_file_count)

请注意，现在标识符tracks_file_count、next_url 和features_file_count 被两次用作函数的参数和全局变量/循环变量。 next_url 现在由创建 tracks 字典的函数返回。