Latitude and longitude from GPSInfo tag from PIL image._getexif() crashes in V3.4

[cvp]

Latitude and longitude from GPSInfo tag from PIL image._getexif() crashes in V3.4 With error

Problem does not come from Pythonista it-self but is due to upgrade of PIL, good to know.

    lat,lon, lat_lon_txt = get_gps(img)
  File "/private/var/mobile/Containers/Shared/AppGroup/94C45A26-1F47-4486-9539-896F8F44AA91/Pythonista3/Documents/MesApps/Localisation photo.py", line 96, in get_gps
    lat = convert_to_degrees(gps_latitude)
  File "/private/var/mobile/Containers/Shared/AppGroup/94C45A26-1F47-4486-9539-896F8F44AA91/Pythonista3/Documents/MesApps/Localisation photo.py", line 109, in convert_to_degrees
    d0 = value[0][0]
TypeError: 'IFDRational' object is not subscriptable

def get_gps(image):
	gps_latitude      = None
	gps_latitude_ref  = None
	gps_longitude     = None
	gps_longitude_ref = None
	exif_info = image._getexif()							# Extract exifs from photo
	#print(exif_info)
	if exif_info:
		for tag, value in exif_info.items():		# Loop on exifs of photo	
			decoded = TAGS.get(tag, tag)					# Exif code
			print(decoded,value)
			if decoded == "GPSInfo":							# Exif is GPSInfo
				for t in value:											# Loop on sub-exifs
					sub_decoded = GPSTAGS.get(t, t)		# Sub-exif code
					print(sub_decoded,value[t])
					if   sub_decoded == 'GPSLatitude':
						gps_latitude = value[t]
					elif sub_decoded == 'GPSLatitudeRef':
						gps_latitude_ref = value[t]		
					elif sub_decoded == 'GPSLongitude':
						gps_longitude = value[t]
					elif sub_decoded == 'GPSLongitudeRef':
						gps_longitude_ref = value[t]
					
				if gps_latitude and gps_latitude_ref and gps_longitude and gps_longitude_ref:
					lat = convert_to_degrees(gps_latitude)
					lat_lon_txt = str(lat)+gps_latitude_ref
					if gps_latitude_ref != "N":                     
						lat = 0 - lat
					lon = convert_to_degrees(gps_longitude)
					lat_lon_txt = lat_lon_txt+' - '+str(lon)+gps_longitude_ref
					if gps_longitude_ref != "E":
						lon = 0 - lon
					return lat, lon, lat_lon_txt
	return False,False,None
	
def convert_to_degrees(value):
	# convert the GPS coordinates d m s to degrees in float
	d0 = value[0][0]
	d1 = value[0][1]
	d = float(d0) / float(d1)

	m0 = value[1][0]
	m1 = value[1][1]
	m = float(m0) / float(m1)

	s0 = value[2][0]
	s1 = value[2][1]
	s = float(s0) / float(s1)

	return d + (m / 60.0) + (s / 3600.0)

It seems that with Pillow version 7 (and most likely below) the degree, minute and second values were tuples that were to be interpreted as fractions (the first value being the numerator and the second the denominator). Pillow version 8 provides just a number that can be used directly

Thus, if you use this GPSInfo, you have to change your code...