def find(self, image_file):
'''More useful - find the best format handler in the registry for your
image file. N.B. this is in principle a factory function.'''
self.setup()
# Recursively check whether any of the children understand
# image_file, in which case they are preferred over the parent
# format.
def recurse(format, image_file):
for child in sorted(format._children, key=lambda x: x.__name__):
try:
if child.understand(image_file):
return recurse(child, image_file)
except Exception:
pass
return format
for format in sorted(self._formats, key=lambda x: x.__name__):
try:
if format.understand(image_file):
return recurse(format, image_file)
except Exception:
pass
# Try opening the file; this could be an easy reason for failure
if not Format.is_url(image_file):
try:
with open(image_file) as f:
pass
except IOError as e:
# Assume that the OS file error makes sense to the user
raise SorryIOError(e)
raise IOError('no format support found for %s' % image_file)
