fixes #707

Author: jph00

fastcore/_modidx.py

@@ -669,6 +669,7 @@
                                 'fastcore.xtras.globtastic': ('xtras.html#globtastic', 'fastcore/xtras.py'),
                                 'fastcore.xtras.hl_md': ('xtras.html#hl_md', 'fastcore/xtras.py'),
                                 'fastcore.xtras.image_size': ('xtras.html#image_size', 'fastcore/xtras.py'),
+                                'fastcore.xtras.img_bytes': ('xtras.html#img_bytes', 'fastcore/xtras.py'),
                                 'fastcore.xtras.is_listy': ('xtras.html#is_listy', 'fastcore/xtras.py'),
                                 'fastcore.xtras.is_namedtuple': ('xtras.html#is_namedtuple', 'fastcore/xtras.py'),
                                 'fastcore.xtras.is_typeddict': ('xtras.html#is_typeddict', 'fastcore/xtras.py'),

fastcore/xtras.py

@@ -6,16 +6,16 @@
 from __future__ import annotations
 
 # %% auto 0
-__all__ = ['spark_chars', 'UNSET', 'walk', 'globtastic', 'maybe_open', 'mkdir', 'image_size', 'bunzip', 'loads', 'loads_multi',
-           'dumps', 'untar_dir', 'repo_details', 'shell', 'ssh', 'rsync_multi', 'run', 'open_file', 'save_pickle',
-           'load_pickle', 'parse_env', 'expand_wildcards', 'dict2obj', 'obj2dict', 'repr_dict', 'is_listy', 'mapped',
-           'IterLen', 'ReindexCollection', 'SaveReturn', 'trim_wraps', 'save_iter', 'asave_iter', 'friendly_name',
-           'n_friendly_names', 'exec_eval', 'get_source_link', 'truncstr', 'sparkline', 'modify_exception',
-           'round_multiple', 'set_num_threads', 'join_path_file', 'autostart', 'EventTimer', 'stringfmt_names',
-           'PartialFormatter', 'partial_format', 'utc2local', 'local2utc', 'trace', 'modified_env', 'ContextManagers',
-           'shufflish', 'console_help', 'hl_md', 'type2str', 'dataclass_src', 'Unset', 'nullable_dc', 'make_nullable',
-           'flexiclass', 'asdict', 'vars_pub', 'is_typeddict', 'is_namedtuple', 'CachedIter', 'CachedAwaitable',
-           'reawaitable', 'flexicache', 'time_policy', 'mtime_policy', 'timed_cache']
+__all__ = ['spark_chars', 'UNSET', 'walk', 'globtastic', 'maybe_open', 'mkdir', 'image_size', 'img_bytes', 'bunzip', 'loads',
+           'loads_multi', 'dumps', 'untar_dir', 'repo_details', 'shell', 'ssh', 'rsync_multi', 'run', 'open_file',
+           'save_pickle', 'load_pickle', 'parse_env', 'expand_wildcards', 'dict2obj', 'obj2dict', 'repr_dict',
+           'is_listy', 'mapped', 'IterLen', 'ReindexCollection', 'SaveReturn', 'trim_wraps', 'save_iter', 'asave_iter',
+           'friendly_name', 'n_friendly_names', 'exec_eval', 'get_source_link', 'truncstr', 'sparkline',
+           'modify_exception', 'round_multiple', 'set_num_threads', 'join_path_file', 'autostart', 'EventTimer',
+           'stringfmt_names', 'PartialFormatter', 'partial_format', 'utc2local', 'local2utc', 'trace', 'modified_env',
+           'ContextManagers', 'shufflish', 'console_help', 'hl_md', 'type2str', 'dataclass_src', 'Unset', 'nullable_dc',
+           'make_nullable', 'flexiclass', 'asdict', 'vars_pub', 'is_typeddict', 'is_namedtuple', 'CachedIter',
+           'CachedAwaitable', 'reawaitable', 'flexicache', 'time_policy', 'mtime_policy', 'timed_cache']
 
 # %% ../nbs/03_xtras.ipynb
 from .imports import *
@@ -126,6 +126,14 @@ def _png_size(f):
     d = dict(png=_png_size, gif=_gif_size, jpeg=_jpg_size)
     with maybe_open(fn, 'rb') as f: return d[imghdr.what(f)](f)
 
+# %% ../nbs/03_xtras.ipynb
+def img_bytes(img, fmt='PNG'):
+    # Convert PIL `img` to bytes in format `fmt`
+    from io import BytesIO
+    buf=BytesIO()
+    img.save(buf, format=fmt)
+    return buf.getvalue()
+
 # %% ../nbs/03_xtras.ipynb
 def bunzip(fn):
     "bunzip `fn`, raising exception if output already exists"

nbs/03_xtras.ipynb

@@ -435,6 +435,76 @@
     "test_eq(image_size(fname), (1200,803))"
    ]
   },
+  {
+   "cell_type": "code",
+   "execution_count": null,
+   "metadata": {},
+   "outputs": [],
+   "source": [
+    "from PIL import Image\n",
+    "from IPython.display import Image as IPImage"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": null,
+   "metadata": {},
+   "outputs": [
+    {
+     "data": {
+      "image/jpeg": "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",
+      "image/png": "iVBORw0KGgoAAAANSUhEUgAAADIAAAAyCAIAAACRXR/mAAAAfUlEQVR4AWL8zzAYAdNgdBTDqLNIAqORSAoYDS1SwGhokQJGQ4sUMBpapIDR0CIFjIYWKWA0tEgBo6FFChgNLVLAaGiRAkZDixQwGlqkgNHQIgWMhhYpYDS0SAGjoUUKGA0tUsBoaJECRkOLFDAaWqSA0dAiBYyGFmCkhBYAQaoBY/NmMJ4AAAAASUVORK5CYII=",
+      "text/plain": [
+       "<PIL.Image.Image image mode=RGB size=50x50>"
+      ]
+     },
+     "execution_count": null,
+     "metadata": {},
+     "output_type": "execute_result"
+    }
+   ],
+   "source": [
+    "img = Image.new('RGB', (50, 50), color='red')\n",
+    "img"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": null,
+   "metadata": {},
+   "outputs": [],
+   "source": [
+    "#| export\n",
+    "def img_bytes(img, fmt='PNG'):\n",
+    "    # Convert PIL `img` to bytes in format `fmt`\n",
+    "    from io import BytesIO\n",
+    "    buf=BytesIO()\n",
+    "    img.save(buf, format=fmt)\n",
+    "    return buf.getvalue()"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": null,
+   "metadata": {},
+   "outputs": [
+    {
+     "data": {
+      "image/png": "iVBORw0KGgoAAAANSUhEUgAAADIAAAAyCAIAAACRXR/mAAAAZklEQVR4nM3OMQEAMAyAMIZ/z52B/iUK8oYiSZIkSZIkSZIkSZIkSZIkSZIkSZIkSZIkSZIkSZIkSZIkSZIkSZIkSZIkSZIkSZIkSZIkSZIkSZIkSZIkSZIkSZIkSZIkSZIkrwO7D0GqAWPcq78HAAAAAElFTkSuQmCC",
+      "text/plain": [
+       "<IPython.core.display.Image object>"
+      ]
+     },
+     "execution_count": null,
+     "metadata": {},
+     "output_type": "execute_result"
+    }
+   ],
+   "source": [
+    "ib = img_bytes(img)\n",
+    "IPImage(ib)"
+   ]
+  },
   {
    "cell_type": "code",
    "execution_count": null,