IPython console: Improve banner when IPython version is missing

Also, add a small test to check that the version is shown as expected
for internal and external interpreters.

spyder/plugins/ipythonconsole/tests/test_ipythonconsole.py

@@ -13,6 +13,7 @@
 # Standard library imports
 import os
 import os.path as osp
+import re
 import shutil
 import sys
 from textwrap import dedent
@@ -1382,11 +1383,16 @@ def test_kernel_kill(ipyconsole, qtbot, external_interpreter):
     assert len(old_open_comms) == 1
     with qtbot.waitSignal(shell.sig_prompt_ready, timeout=30000):
         shell.execute(crash_string)
-    assert crash_string in shell._control.toPlainText()
-    assert "The kernel died, restarting..." in shell._control.toPlainText()
+
+    console_text = shell._control.toPlainText()
+    assert crash_string in console_text
+    assert "The kernel died, restarting..." in console_text
 
     # Check we don't show error generated by `conda run`
-    assert "conda.cli.main_run" not in shell._control.toPlainText()
+    assert "conda.cli.main_run" not in console_text
+
+    # Check IPython version is shown as expected
+    assert list(re.finditer(r"IPython \d+\.", console_text))
 
     # Check a new comm replaced the old one
     new_open_comms = list(shell.kernel_handler.kernel_comm._comms.keys())

spyder/plugins/ipythonconsole/widgets/main_widget.py

@@ -13,6 +13,7 @@
 import os
 import os.path as osp
 import shlex
+import subprocess
 import sys
 
 # Third-party imports
@@ -1368,24 +1369,27 @@ def interpreter_versions(self, path_to_custom_interpreter=None):
                 ipython_version=release.version
             )
         else:
-            import subprocess
             versions = {}
             pyexec = self.get_conf('executable', section='main_interpreter')
             if path_to_custom_interpreter:
                 pyexec = path_to_custom_interpreter
-            py_cmd = u'%s -c "import sys; print(sys.version)"' % pyexec
+
+            py_cmd = '%s -c "import sys; print(sys.version)"' % pyexec
             ipy_cmd = (
-                u'%s -c "import IPython.core.release as r; print(r.version)"'
+                '%s -c "import IPython.core.release as r; print(r.version)"'
                 % pyexec
             )
+
             for cmd in [py_cmd, ipy_cmd]:
                 try:
                     # Use clean environment
                     proc = programs.run_shell_command(cmd, env={})
                     output, _err = proc.communicate()
                 except subprocess.CalledProcessError:
                     output = ''
+
                 output = output.decode().split('\n')[0].strip()
+
                 if 'IPython' in cmd:
                     versions['ipython_version'] = output
                 else:

spyder/plugins/ipythonconsole/widgets/shell.py

@@ -724,8 +724,15 @@ def long_banner(self):
             'Python %s\n' % py_ver,
             'Type "copyright", "credits" or "license" for more information.',
             '\n\n',
-            'IPython %s -- An enhanced Interactive Python.\n' % ipy_ver
         ]
+
+        if ipy_ver:
+            banner_parts.append(
+                'IPython %s -- An enhanced Interactive Python.\n' % ipy_ver
+            )
+        else:
+            banner_parts.append('IPython -- An enhanced Interactive Python.\n')
+
         banner = ''.join(banner_parts)
 
         # Pylab additions