Analyse XML - Problème de performance
Bonsoir.
J'utilise actuellement un script pour extraire des infos de mes playlists iTunes à partir du fichier XML propre à iTunes. Or ce fichier étant volumineux, d'une taille de 52,6 Mo, l'utilisation de mon script est très consommatrice de mémoire vive. Je souhaite donc améliorer ceci.
Voici la structure générale du fichier XML. Tout d'abord les chansons sont stockées ainsi.
Code:
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
| <key>6642</key>
<dict>
<key>Track ID</key><integer>6642</integer>
<key>Name</key><string>...</string>
<key>Artist</key><string>...</string>
<key>Album Artist</key><string>...</string>
<key>Composer</key><string>...</string>
<key>Album</key><string>...</string>
<key>Genre</key><string>...</string>
<key>Kind</key><string>...</string>
<key>Size</key><integer>...</integer>
<key>Total Time</key><integer>...</integer>
<key>Track Number</key><integer>...</integer>
<key>Year</key><integer>...</integer>
<key>Date Modified</key><date>...</date>
<key>Date Added</key><date>...</date>
<key>Bit Rate</key><integer>...</integer>
<key>Sample Rate</key><integer>...</integer>
<key>Persistent ID</key><string>...</string>
<key>Track Type</key><string>...</string>
<key>Location</key><string>...</string>
<key>File Folder Count</key><integer>...</integer>
<key>Library Folder Count</key><integer>...</integer>
</dict> |
Les playlists sont stockées comme suit.
Code:
1
2
3
4
5
6
7
8
9
10
11
12
13
14
| <dict>
<key>Name</key><string>nameOfThPlaylist</string>
<key>Playlist ID</key><integer>87635</integer>
<key>Playlist Persistent ID</key><string>9A4C8A8C60D68000</string>
<key>Parent Persistent ID</key><string>60F56F7F0F05D2B3</string>
<key>All Items</key><true/>
<key>Playlist Items</key>
<array>
<dict>
<key>Track ID</key><integer>12010</integer>
</dict>
...
</array>
</dict> |
Globalement, le fichier XML ressemble à ceci.
Code:
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
| <?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE plist PUBLIC "-//Apple Computer//DTD PLIST 1.0//EN" "http://www.apple.com/DTDs/PropertyList-1.0.dtd">
<plist version="1.0">
<dict>
<key>Major Version</key><integer>1</integer>
<key>Minor Version</key><integer>1</integer>
<key>Application Version</key><string>9.2</string>
<key>Features</key><integer>5</integer>
<key>Show Content Ratings</key><true/>
<key>Music Folder</key><string>...</string>
<key>Library Persistent ID</key><string>44A5D91826563D8D</string>
<key>Tracks</key>
<dict>
The definitions of the song (see before)
</dict>
<key>Playlists</key>
<array>
<dict>
<key>Name</key><string>...</string>
<key>Playlist ID</key><integer>...</integer>
<key>Playlist Persistent ID</key><string>AF0AD7E90AB4E728</string>
<key>Parent Persistent ID</key><string>B03891ABA2B5AB4C</string>
<key>All Items</key><true/>
<key>Folder</key><true/>
<key>Playlist Items</key>
<array>
<dict>
<key>Track ID</key><integer>...</integer>
</dict>
<dict>
<key>Track ID</key><integer>...</integer>
</dict>
</array>
</dict>
<dict>
The definitions of the playlists in the folder.
</dict>
</array>
</dict>
</plist> |
Mon code Python ressemble à l'horreur qui suit.
Code:
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
| #! /usr/bin/env python
import xml.etree.ElementTree as etree
import urllib.request
SONGS = {}
PLAYLISTS_ID_CONTAINER = {}
PLAYLISTS_FOLDER = {}
FOLDERS = {'': {}} # This is for playlists that are not in a folder.
ALIAS = {
'Track ID': "newSong",
'Name' : "songName",
'Artist' : "artistName",
'Composer': "composer",
'Album': "album",
'Genre': "style",
'Total Time': "time_ms",
'Location': "path"
}
def getSongs(elem):
lastKey = ''
newSong = False
text = elem.text or ""
for e in elem:
textInsideCurrentTag = getSongs(e).strip()
# A new song
if e.tag == 'key':
if textInsideCurrentTag in ALIAS:
lastKey = ALIAS[textInsideCurrentTag]
if e.tag == 'integer':
if lastKey == "newSong":
currentIndexSong = cleanSpecialCharacters(textInsideCurrentTag)
SONGS[currentIndexSong] = {}
lastKey = ""
elif lastKey in [ "time_ms" ]:
SONGS[currentIndexSong][lastKey] = cleanSpecialCharacters(textInsideCurrentTag)
lastKey = ""
elif e.tag == 'string' and lastKey == "path":
textInsideCurrentTag = cleanSpecialCharacters(textInsideCurrentTag)
if textInsideCurrentTag.startswith(r'file://localhost'):
textInsideCurrentTag = textInsideCurrentTag [len(r'file://localhost'):]
SONGS[currentIndexSong][lastKey] = cleanSpecialCharacters(textInsideCurrentTag)
lastKey = ""
elif e.tag == 'string' \
and lastKey in [
"songName",
"artistName" ,
"composer",
"album",
"style"
]:
SONGS[currentIndexSong][lastKey] = cleanSpecialCharacters(textInsideCurrentTag)
lastKey = ""
if e.tail:
text += e.tail
return text
def getPlaylist(elem):
global THE_PLAYLIST_IDS
global PLAYLIST_NAME
global WE_HAVE_FOLDER
global ID_CONTAINER
global ID_OBJECT
lastKey = ''
text = elem.text or ""
for e in elem:
textInsideCurrentTag = getPlaylist(e).strip()
# A new song
if e.tag == 'key':
if textInsideCurrentTag == 'Track ID':
lastKey = ALIAS[textInsideCurrentTag]
elif textInsideCurrentTag == 'Folder':
WE_HAVE_FOLDER = True
elif textInsideCurrentTag == 'Name':
lastKey = 'playlistName'
elif textInsideCurrentTag == 'Parent Persistent ID':
lastKey = 'inFolder'
elif textInsideCurrentTag == 'Playlist Persistent ID':
lastKey = 'identity'
elif e.tag == 'integer' and lastKey == "newSong":
THE_PLAYLIST_IDS.append(textInsideCurrentTag)
lastKey = ""
elif e.tag == 'string':
if PLAYLIST_NAME == '' and lastKey == 'playlistName':
PLAYLIST_NAME = e.text.strip()
lastKey = ""
elif lastKey == 'inFolder':
ID_CONTAINER = e.text.strip()
lastKey = ""
elif lastKey == 'identity':
ID_OBJECT = e.text.strip()
lastKey = ""
if e.tail:
text += e.tail
return text
def printFolder(idObject):
global FOLDERS
if 'container' in FOLDERS[idObject]:
if FOLDERS[idObject]['container']:
return printFolder(FOLDERS[idObject]['container']) + '/' + FOLDERS[idObject]['name']
return FOLDERS[idObject]['name']
return ''
# Here we go...
print("",
"===== READING iTunes Library INFOS =====",
"1) Building the tree of the XML iTunes file. This can take a long time...",
sep = '\n')
tree = etree.parse(pathOfThePlaylist)
print("2) Looking for all the songs. This can take a long time...")
getSongs(tree.getroot().find('dict/dict'))
print("3) Looking for all the playlists...")
folders = []
for onePlaylist in tree.getroot().findall('dict/array/dict'):
THE_PLAYLIST_IDS = []
PLAYLIST_NAME = ''
WE_HAVE_FOLDER = False
ID_CONTAINER = ''
ID_OBJECT = ''
getPlaylist(onePlaylist)
if WE_HAVE_FOLDER:
FOLDERS[ID_OBJECT] = { 'name': PLAYLIST_NAME,
'container': ID_CONTAINER
}
else:
if ID_CONTAINER in PLAYLISTS_ID_CONTAINER:
PLAYLISTS_ID_CONTAINER[ID_CONTAINER][PLAYLIST_NAME]= THE_PLAYLIST_IDS
else:
PLAYLISTS_ID_CONTAINER[ID_CONTAINER] = {PLAYLIST_NAME: THE_PLAYLIST_IDS}
for oneIdContainer in PLAYLISTS_ID_CONTAINER:
PLAYLISTS_FOLDER[printFolder(oneIdContainer)] = PLAYLISTS_ID_CONTAINER[oneIdContainer]
print("4) Reading iTunes Library infos is finished.") |
Dans le code ci-dessus, c'est l'utilisation de etree.parse(pathOfThePlaylist) qui pose problème. Comment éviter son emploi ?
