Why are my pictures corrupted after downloading and writing them in python?

Question

Preface

This is my first post on stackoverflow so I apologize if I mess up somewhere. I searched the internet and stackoverflow heavily for a solution to my issues but I couldn't find anything.

Situation

What I am working on is creating a digital photo frame with my raspberry pi that will also automatically download pictures from my wife's facebook page. Luckily I found someone who was working on something similar:

https://github.com/samuelclay/Raspberry-Pi-Photo-Frame

One month ago this gentleman added the download_facebook.py script. This is what I needed! So a few days ago I started working on this script to get it working in my windows environment first (before I throw it on the pi). Unfortunately there is no documentation specific to that script and I am lacking in python experience.

Based on the from urllib import urlopen statement, I can assume that this script was written for Python 2.x. This is because Python 3.x is now from urlib import request.

So I installed Python 2.7.9 interpreter and I've had fewer issues than when I was attempting to work with Python 3.4.3 interpreter.

Problem

I've gotten the script to download pictures from the facebook account; however, the pictures are corrupted.

Here is pictures of the problem: https://i.sstatic.net/MiuLg.jpg

Now, I originally was using Python 3.4.3 and had issues with my method urlrequest(url) (see code at bottom of post) and how it was working with the image data. I tried decoding with different formats such as utf-8 and utf-16 but according to the content headers, it shows utf-8 format (I think).

Conclusion

I'm not quite sure if the problem is with downloading the image or with writing the image to the file.

If anyone can help me with this I'd be forever grateful! Also let me know what I can do to improve my posts in the future.

Thanks in advance.

Code

from urllib import urlopen
from json import loads
from sys import argv
import dateutil.parser as dateparser
import logging

# plugin your username and access_token (Token can be get and
# modified in the Explorer's Get Access Token button):
# https://graph.facebook.com/USER_NAME/photos?type=uploaded&fields=source&access_token=ACCESS_TOKEN_HERE
FACEBOOK_USER_ID = "**USER ID REMOVED"
FACEBOOK_ACCESS_TOKEN = "** TOKEN REMOVED - GET YOUR OWN **"

def get_logger(label='lvm_cli', level='INFO'):
    """
    Return a generic logger.
    """
    format = '%(asctime)s - %(levelname)s - %(message)s'
    logging.basicConfig(format=format)
    logger = logging.getLogger(label)
    logger.setLevel(getattr(logging, level))
    return logger

def urlrequest(url):
    """
    Make a url request
    """
    req = urlopen(url)
    data = req.read()
    return data

def get_json(url):
    """
    Make a url request and return as a JSON object
    """
    res = urlrequest(url)
    data = loads(res)
    return data

def get_next(data):
    """
    Get next element from facebook JSON response,
    or return None if no next present.
    """
    try:
        return data['paging']['next']
    except KeyError:
        return None

def get_images(data):
    """
    Get all images from facebook JSON response,
    or return None if no data present.
    """
    try:
        return data['data']
    except KeyError:
        return []

def get_all_images(url):
    """
    Get all images using recursion.
    """
    data = get_json(url)
    images = get_images(data)
    next = get_next(data)

    if not next:
        return images
    else:
        return images + get_all_images(next)

def get_url(userid, access_token):
    """
    Generates a useable facebook graph API url
    """
    root = 'https://graph.facebook.com/'
    endpoint = '%s/photos?type=uploaded&fields=source,updated_time&access_token=%s' % \
                (userid, access_token)
    return '%s%s' % (root, endpoint)

def download_file(url, filename):
    """
    Write image to a file.
    """
    data = urlrequest(url)
    path = 'C:/photos/%s' % filename
    f = open(path, 'w')
    f.write(data)
    f.close()

def create_time_stamp(timestring):
    """
    Creates a pretty string from time
    """
    date = dateparser.parse(timestring)
    return date.strftime('%Y-%m-%d-%H-%M-%S')

def download(userid, access_token):
    """
    Download all images to current directory.
    """
    logger = get_logger()
    url = get_url(userid, access_token)
    logger.info('Requesting image direct link, please wait..')
    images = get_all_images(url)

    for image in images:
        logger.info('Downloading %s' % image['source'])
        filename = '%s.jpg' % create_time_stamp(image['created_time'])
        download_file(image['source'], filename)

if __name__ == '__main__':
    download(FACEBOOK_USER_ID, FACEBOOK_ACCESS_TOKEN)

Answer 1

Answering the question of why @Alastair's solution from the comments worked:

f = open(path, 'wb')

From https://docs.python.org/2/tutorial/inputoutput.html#reading-and-writing-files:

On Windows, 'b' appended to the mode opens the file in binary mode, so there are also modes like 'rb', 'wb', and 'r+b'. Python on Windows makes a distinction between text and binary files; the end-of-line characters in text files are automatically altered slightly when data is read or written. This behind-the-scenes modification to file data is fine for ASCII text files, but it’ll corrupt binary data like that in JPEG or EXE files. Be very careful to use binary mode when reading and writing such files. On Unix, it doesn’t hurt to append a 'b' to the mode, so you can use it platform-independently for all binary files.

(I was on a Mac, which explains why the problem wasn't reproduced for me.)