Python3 script to rename files based on EXIF info

rename_exif.py

#!/usr/local/bin/python3
import os
from PIL import Image
from hachoir.parser import createParser
from hachoir.metadata import extractMetadata

# Parameters
dir = '/path/to/media/files'
image_extensions = ['.jpg']
video_extensions = ['.mp4']

# Processing state
rename_dict = {}  # new_name => old_name
errors_dict = {}  # old_name => error description
firsty_dict = {}  # stub => new_name when no collision so far
suffix_dict = {}  # stub => suffix index

try:
  filenames = os.listdir(dir)
except FileNotFoundError:
  print(f"No such file or directory: '{dir}'")
  exit(1)


class UnrecognizedExtensionException(Exception):
  pass
class TooManyCollisionsException(Exception):
  pass

# Parse file metadata in order to find the relevant date/time info
def extractExifInfo(abs_name, ext):
  # Actual date/time when the photo was taken, e.g. 2015:12:31 23:59:59
  if ext in image_extensions:
    created_exif = Image.open(abs_name)._getexif()[36867]
    return created_exif.split(' ')[0].split(':')

  # Date/time of creation, e.g. 2015-12-31 23:59:59
  # FIXME: On macOS it appears to be the file's "Modified" date.
  # How can we access the actual "Recorded" date?
  if ext in video_extensions:
    with createParser(abs_name) as parser:
      metadata = extractMetadata(parser)
      exif_dict = metadata.exportDictionary()['Metadata']
      return exif_dict['Creation date'].split(' ')[0].split('-')

  raise UnrecognizedExtensionException


# Construct date-based filename with suffix in case of collisions
def constructNewFileName(year, month, day, ext):
  # No collision, keep it simple, e.g. 2015-12-31.jpg
  stub = f"{year}-{month}-{day}"
  if not (stub in firsty_dict.keys() or stub in suffix_dict.keys()):
    firsty_dict[stub] = stub + ext
    return stub + ext

  # Insert suffix for existing entry on first collisions, e.g. 2015-12-31a.jpg
  if stub in firsty_dict:
    assert(firsty_dict[stub] in rename_dict)
    old_name = rename_dict.pop(firsty_dict.pop(stub))
    rename_dict[stub + 'a' + ext] = old_name
    suffix_dict[stub] = 1

  # Bail out if we ran out of suffixes
  suffix_dict[stub] += 1
  if suffix_dict[stub] > ord('z') - ord('a'):
    raise TooManyCollisionsException("Last available suffix already taken: 'z'")

  # Add the new entry with suffix, e.g. 2015-12-31b.jpg
  suffix = chr(ord('a') + suffix_dict[stub])
  return stub + suffix + ext


# Process all files and construct new names
for filename in filenames:
  try:
    abs_name = os.path.join(dir, filename)
    _, extension = os.path.splitext(filename)
    year, month, day = extractExifInfo(abs_name, extension.lower())
    new_name = constructNewFileName(year, month, day, extension)
    assert(not new_name in rename_dict.keys())
    rename_dict[new_name] = filename
    continue
  except KeyError:
    errors_dict[filename] = 'Error parsing EXIF data'
  except UnrecognizedExtensionException:
    errors_dict[filename] = 'Unrecognized extension'
  except TooManyCollisionsException as ex:
    errors_dict[filename] = 'Too many collisions. ' + str(ex)
  except Exception as ex:
    errors_dict[filename] = 'Unknown error: ' + type(ex).__name__


# Print out the mapping
rindent = len(max(filenames, key=len)) + 1
for new_name, old_name in sorted(rename_dict.items()):
  print(old_name.rjust(rindent) + '    =>    ' + new_name.ljust(35))
print("\nSkipping:")
for old_name, err in sorted(errors_dict.items()):
  print(old_name.rjust(rindent) + '          ' + err)


# Write changes to disk
print(f"\nAbout to rename {len(rename_dict.keys())} files")
if input("Proceed? (y/n) ") != 'y':
  print("Cancelled\n")
  exit(1)

for new_name, old_name in rename_dict.items():
  os.rename(os.path.join(dir, old_name), os.path.join(dir, new_name))

print("Done\n")