display images (untested)

biocham_kernel/images.py

+# very much inspired form the example bash_kernel
+# https://raw.githubusercontent.com/takluyver/bash_kernel/
+import base64
+import imghdr
+import os
+
+
+def display_data_for_image(filename):
+    with open(filename, 'rb') as f:
+        image = f.read()
+    os.unlink(filename)
+
+    image_type = imghdr.what(None, image)
+    if image_type is None:
+        raise ValueError("Not a valid image: %s" % image)
+
+    image_data = base64.b64encode(image).decode('ascii')
+    content = {
+        'data': {
+            'image/' + image_type: image_data
+        },
+        'metadata': {}
+    }
+    return content
+
+
+def extract_image_filenames(output):
+    output_lines = []
+    image_filenames = []
+
+    for line in output.split("\n"):
+        if line.startswith('<img src="'):
+            filename = line.rstrip().split('"')[1]
+            image_filenames.append(filename)
+        else:
+            output_lines.append(line)
+
+    output = "\n".join(output_lines)
+    return image_filenames, output

biocham_kernel/kernel.py

@@ -3,6 +3,8 @@ from subprocess import check_output
 from ipykernel.kernelbase import Kernel
 from pexpect import replwrap
 
+from .images import extract_image_filenames, display_data_for_image
+
 
 class BiochamKernel(Kernel):
     implementation = 'Biocham'
@@ -20,19 +22,32 @@ class BiochamKernel(Kernel):
         Kernel.__init__(self, **kwargs)
         self._start_biocham()
 
-
     def _start_biocham(self):
-        self.biocham = replwrap.REPLWrapper( 'biocham4 --jupyter', 'biocham: ', None)
-
+        self.biocham = replwrap.REPLWrapper(
+            'biocham4 --jupyter',
+            'biocham: ',
+            None
+        )
 
     def do_execute(self, code, silent, store_history=True,
                    user_expressions=None, allow_stdin=False):
         output = self.biocham.run_command(code)
 
+        image_filenames, output = extract_image_filenames(output)
+
         if not silent:
             stream_content = {'name': 'stdout', 'text': output}
             self.send_response(self.iopub_socket, 'stream', stream_content)
 
+        for filename in image_filenames:
+            try:
+                data = display_data_for_image(filename)
+            except ValueError as e:
+                message = {'name': 'stdout', 'text': str(e)}
+                self.send_response(self.iopub_socket, 'stream', message)
+            else:
+                self.send_response(self.iopub_socket, 'display_data', data)
+
         return {'status': 'ok',
                 # The base class increments the execution count
                 'execution_count': self.execution_count,