Reportlab и PIL: для распаковки требуется строковый аргумент длиной 1 Библиотека изображений недоступна, невозможно импортировать растровые изображения только в формате JPEG

Question

У меня проблема с использованием ReportLab и PIL (в проекте Flask) с использованием виртуальной машины Vagrant (2.2.3)

Ошибка обнаружена с использованием функции readJPEGInfo () .Файл PNG ( -rwxrwxr-- 1 www-data www-data 21K juin 22 2018 ) находится там:

site_media/img/84/5_1_pied_de_page.png: PNG image data, 1066 x 47, 8-bit/color RGBA, non-interlaced

Сообщение об ошибке:

(unpack requires a string argument of length 1 Imaging Library not available, unable to import bitmaps only jpegs 
fileName='/var/www/my_project/my_project/site_media/img/20/5_1_pied_de_page.png' identity=[ImageReader@0x7fdd75f2a110 
filename='/var/www/my_project/my_project/site_media/img/20/5_1_pied_de_page.png'] 
fileName='/var/www/my_project/my_project/site_media/img/20/5_1_pied_de_page.png' identity=[ImageReader@0x7fdd75f2a110 
filename='/var/www/my_project/my_project/site_media/img/20/5_1_pied_de_page.png'] --> <class 'struct.error'> => Traceback (most recent call last): File "/var/www/my_project/my_project/flask_my_project/views.py", line 206, in zonesmeteo createDisplay(t, config, tabAlerts, demain, message)

File "/var/www/my_project/my_project/flask_my_project/utils.py", line 29, in createDisplay tr.generateFiles() 
File "/var/www/my_project/my_project/cron_dept_treatments/84.py", line 64, in generateFiles self.dicoFolders) 
File "/var/www/my_project/my_project/cron_dept_treatments/84.py", line 258, in __init__ table5.drawOn(self.c,15,12) 
File "/home/vagrant/.virtualenvs/my_project/lib/python2.7/site-packages/reportlab/platypus/flowables.py", line 111, in drawOn self._drawOn(canvas)
File "/home/vagrant/.virtualenvs/my_project/lib/python2.7/site-packages/reportlab/platypus/flowables.py", line 92, in _drawOn self.draw()#this is the bit you overload 
File "/home/vagrant/.virtualenvs/my_project/lib/python2.7/site-packages/reportlab/platypus/tables.py", line 1425, in draw self._drawCell(cellval, cellstyle, (colpos, rowpos), (colwidth, rowheight)) 
File "/home/vagrant/.virtualenvs/my_project/lib/python2.7/site-packages/reportlab/platypus/tables.py", line 1558, in _drawCell v.drawOn(self.canv,x,y) 
File "/home/vagrant/.virtualenvs/my_project/lib/python2.7/site-packages/reportlab/platypus/flowables.py", line 111, in drawOn self._drawOn(canvas)
File "/home/vagrant/.virtualenvs/my_project/lib/python2.7/site-packages/reportlab/platypus/flowables.py", line 92, in _drawOn self.draw()#this is the bit you overload 
File "/home/vagrant/.virtualenvs/my_project/lib/python2.7/site-packages/reportlab/platypus/flowables.py", line 511, in draw self.canv.drawImage( self._img or self.filename, 
File "/home/vagrant/.virtualenvs/my_project/lib/python2.7/site-packages/reportlab/platypus/flowables.py", line 481, in __getattr__ self._img = ImageReader(self._file) 
File "/home/vagrant/.virtualenvs/my_project/lib/python2.7/site-packages/reportlab/lib/utils.py", line 810, in __init__ annotateException('\nfileName=%r identity=%s'%(fileName,self.identity())) 
File "/home/vagrant/.virtualenvs/my_project/lib/python2.7/site-packages/reportlab/lib/utils.py", line 1390, in annotateException rl_reraise(t,v,b) 
File "/home/vagrant/.virtualenvs/my_project/lib/python2.7/site-packages/reportlab/lib/utils.py", line 804, in __init__ annotateException('\nImaging Library not available, unable to import bitmaps only jpegs\nfileName=%r identity=%s'%(fileName,self.identity())) 
File "/home/vagrant/.virtualenvs/my_project/lib/python2.7/site-packages/reportlab/lib/utils.py", line 1390, in annotateException rl_reraise(t,v,b) 
File "/home/vagrant/.virtualenvs/my_project/lib/python2.7/site-packages/reportlab/lib/utils.py", line 802, in __init__ self._width,self._height,c=readJPEGInfo(self.fp) 
File "/home/vagrant/.virtualenvs/my_project/lib/python2.7/site-packages/reportlab/pdfbase/pdfutils.py", line 243, in readJPEGInfo x = struct.unpack('B', image.read(1)) error: unpack requires a string argument of length 1 Imaging Library not available, unable to import bitmaps only jpegs fileName='/var/www/my_project/my_project/site_media/img/20/5_1_pied_de_page.png' identity=[ImageReader@0x7fdd75f2a110 

filename='/var/www/my_project/my_project/site_media/img/20/5_1_pied_de_page.png'] fileName='/var/www/my_project/my_project/site_media/img/20/5_1_pied_de_page.png' identity=[ImageReader@0x7fdd75f2a110
filename='/var/www/my_project/my_project/site_media/img/20/5_1_pied_de_page.png'] )

Часть pip freeze (python 2.7):

Pillow==2.6.1
reportlab==3.4.0

Пользователь / группа:

$ cat /etc/group | grep data
www-data:x:33:vagrant,apache,nginx,httpd,www-data,www-user

Итак, я делаю простой тестовый файл python:

import reportlab, PIL
from reportlab.platypus import SimpleDocTemplate
from reportlab.pdfgen import canvas
from reportlab.platypus import Frame, Image

png_file = "/var/www/test/5_1_pied_de_page.png"
img=canvas.Canvas(png_file)

my_doc = SimpleDocTemplate('myfile.pdf')

parts=[]
parts.append(Image(png_file))

my_doc.build(parts)

Те же ошибки:

 File "/home/vagrant/.virtualenvs/my_project/lib/python2.7/site-packages/reportlab/lib/utils.py", line 802, in __init__
    self._width,self._height,c=readJPEGInfo(self.fp)
  File "/home/vagrant/.virtualenvs/my_project/lib/python2.7/site-packages/reportlab/pdfbase/pdfutils.py", line 243, in readJPEGInfo
    x = struct.unpack('B', image.read(1))
struct.error: unpack requires a string argument of length 1
Imaging Library not available, unable to import bitmaps only jpegs
fileName='/var/www/my_project/my_project/site_media/img/84/5_1_pied_de_page.png' identity=[ImageReader@0x7fc9223f3e50 filename='/var/www/my_project/my_project/site_media/img/84/5_1_pied_de_page.png']
fileName='/var/www/my_project/my_project/site_media/img/84/5_1_pied_de_page.png' identity=[ImageReader@0x7fc9223f3e50 filename='/var/www/my_project/my_project/site_media/img/84/5_1_pied_de_page.png']
(my_project)

И в моем тестовом файле я конвертировал PNG в JPG: ошибок нет, но файл pdf пуст:)

Спасибо.

F.

$ uname -a 
Linux vm 4.4.0-131-generic #157-Ubuntu SMP Thu Jul 12 15:51:36 UTC 2018 x86_64 x86_64 x86_64 GNU/Linux

Answer 1

Полагаю, вам нужно поместить его в текучий объект Reportlab. Даже если бы я не использовал PIL напрямую в этом случае, я могу поделиться тем, как заставить его работать (здесь с рамкой, но работает и без). Он работает на большинстве форматов изображений, в том числе PNG, пожалуйста, обратите внимание, я не проверял код ниже.

from reportlab.lib.units import cm
from reportlab.platypus import Image, Frame, PageTemplate, BaseDocTemplate

png_file = "/var/www/test/5_1_pied_de_page.png"

picture_frame = Frame(
    x1              =10 * cm,    # From left
    y1              =26 * cm,    # From bottom
    height          =9 * cm,
    width           =9 * cm)

frontpage = PageTemplate(id='FrontPage', onPage='', frames=[picture_frame])

picture = Image(png_file, 9 * cm, 6 * cm, hAlign='RIGHT')

my_doc = BaseDocTemplate('myfile.pdf', pagesize=A4)
my_doc.addPageTemplates(frontpage)

parts = []
parts.append(picture)

my_doc.build(parts)