add_exif_record.py

import os
import sys
import subprocess
from optparse import OptionParser
from datetime import datetime

def run_shell_script(shell_script):
    """
    Assuming that the script is comming from trusted source.

    :param shell_script: String quaoted shell script.
    :return tuple (boolean, string)
                  True - shell script executed correctly, then tuple includes
                         response in string.
                  False - Some error with executing the script. may be $? is 1
    """
    try:
        output = subprocess.check_output(shell_script, shell=True)
        return True, output
    except subprocess.CalledProcessError:
        return False, ""

def get_file_timestamp_from_filename(filename):
    createtime = filename.split("_")[1]
    filetime = datetime.strptime(createtime, "%Y%m%d")
    return filetime.strftime("%Y:%m:%d %H:%M:%S")

def get_file_timestamp_from_mtime(filename):
    stat = os.stat(filename)
    filetime = datetime.fromtimestamp(stat.st_mtime)
    return filetime.strftime("%Y:%m:%d %H:%M:%S")

def delete_exif_record(filename, exif_record_name):
    done, _ = run_shell_script(
        'exiv2 -M"del {record_name}" {filename}'.format(
            filename=filename, record_name=exif_record_name
        )
    )                                                                                                                                                                                             
    if not done:                                                                                                                                                                                  
        print "Failed to delete the record: {}".format(exif_record_name)                                                                                                                          
                                                                                                                                                                                                  
def add_exif_datetime_original_field(filename, new_timestamp):                                                                                                                                    
    """                                                                                                                                                                                           
    Add Exif.Photo.DateTimeOriginal record in EXIF data of given file.                                                                                                                            
    We only add this record if it doesn't exist already on this file.                                                                                                                             
                                                                                                                                                                                                  
    :param filename: Exif record of this file gets modified.                                                                                                                                      
    :param new_timestamp: The timestamp in "YYYY:MM:DD HH:MM:SS" format.                                                                                                                          
    """                                                                                                                                                                                           
                                                                                                                                                                                                  
    is_rec_exists, _ = run_shell_script(                                                                                                                                                          
        'exiv2 -pt {} | grep Exif.Photo.DateTimeOriginal'.format(filename))                                                                                                                       
    if not is_rec_exists:                                                                                                                                                                         
        updated, _ = run_shell_script(                                                                                                                                                            
            'exiv2 -M"add Exif.Photo.DateTimeOriginal {new_timestamp}" {filename}'.format(                                                                                                        
                new_timestamp=new_timestamp, filename=filename))                                                                                                                                  
        if not updated:                                                                                                                                                                           
            print "Failed to update the Exif record of file: {}".format(filename)                                                                                                                 


if __name__ == "__main__":
    """
    How to use this script.

    1. Picks the timestamp from the filename itself.
        python add_exif_record -t ftime -f IMG_20081214_122122.jpg
        
    2. Pick the timestamp from the file's modification time.
        python add_exif_record -t mtime -f img.jpg 
    """
    parser = OptionParser()
    parser.add_option("-t", "--timestamp", dest="timestamp",
                      help="How to evaluate the file timestamp. default: ftime",
                      default="ftime")
    parser.add_option("-f", "--file", dest="file_name",
                      help="Name of the file need to be updaetd")

    (options, args) = parser.parse_args()

    if options.file_name and options.timestamp:
        if "mtime" in options.timestamp:
            timestamp = get_file_timestamp_from_mtime(options.file_name)
        else:
            timestamp = get_file_timestamp_from_filename(options.file_name)
        add_exif_datetime_original_field(options.file_name, timestamp)