Replace py dependency with termcolor.

Only the colored terminal printing feature of the borderline deprecated py
library is used so swap it out for termcolor which is slimmer. Doing so also
fixes the pains that py's submodule deprecations sculdugery have been causing
PyInstaller users (e.g. #245, #447, plus a new regression specific to pyshark
0.5.2 leading to a `ModuleNotFoundError: No module named 'py._io'`).

src/pyshark/packet/common.py

@@ -1,3 +1,9 @@
+import sys
+import functools
+
+import termcolor
+
+
 class Pickleable(object):
     """
     Base class that implements getstate/setstate, since most of the classes are overriding getattr.
@@ -24,11 +30,12 @@ def __setstate__(self, data):
             setattr(self, key, val)
 
 
-class StrWriter:
-    """A class which mocks the py.io.TerminalWriter to write to an internal buffer"""
-
-    def __init__(self):
-        self.buffer = ""
-
-    def write(self, text, *_, **__):
-        self.buffer += text
+@functools.wraps(termcolor.colored)
+def colored(text, *args, **kwargs):
+    try:
+        enable_color = sys.stdout.isatty()
+    except:
+        enable_color = False
+    if enable_color:
+        return termcolor.colored(text, *args, **kwargs)
+    return text

src/pyshark/packet/layers/base.py

@@ -1,7 +1,7 @@
 import os
 import typing
-
-import py
+import io
+import sys
 
 from pyshark.packet import common
 
@@ -50,21 +50,22 @@ def __getattr__(self, item):
 
     def pretty_print(self, writer=None):
         if not writer:
-            writer = py.io.TerminalWriter()
+            writer = sys.stdout
         if self.layer_name == DATA_LAYER_NAME:
             writer.write('DATA')
             return
 
-        writer.write('Layer %s:' % self.layer_name.upper() + os.linesep, yellow=True, bold=True)
+        text = 'Layer %s:' % self.layer_name.upper() + os.linesep
+        writer.write(common.colored(text, color="yellow", attrs=["bold"]))
         self._pretty_print_layer_fields(writer)
 
-    def _pretty_print_layer_fields(self, terminal_writer: py.io.TerminalWriter):
+    def _pretty_print_layer_fields(self, terminal_writer: io.IOBase):
         raise NotImplementedError()
 
     def __repr__(self):
         return '<%s Layer>' % self.layer_name.upper()
 
     def __str__(self):
-        writer = common.StrWriter()
+        writer = io.StringIO()
         self.pretty_print(writer=writer)
-        return writer.buffer
+        return writer.getvalue()

src/pyshark/packet/layers/ek_layer.py

@@ -1,9 +1,10 @@
 import abc
 import os
+import io
 
-import py
 import typing
 
+from pyshark.packet.common import colored
 from pyshark import ek_field_mapping
 from pyshark.packet.layers.base import BaseLayer
 
@@ -106,24 +107,24 @@ def _field_has_subfields(self, field_ek_name):
                 return True
         return False
 
-    def _pretty_print_layer_fields(self, terminal_writer: py.io.TerminalWriter):
+    def _pretty_print_layer_fields(self, file: io.IOBase):
         for field_name in self.field_names:
             field = self.get_field(field_name)
-            self._pretty_print_field(field_name, field, terminal_writer, indent=1)
+            self._pretty_print_field(field_name, field, file, indent=1)
 
-    def _pretty_print_field(self, field_name, field, terminal_writer, indent=0):
+    def _pretty_print_field(self, field_name, field, file, indent=0):
         prefix = "\t" * indent
         if isinstance(field, EkMultiField):
-            terminal_writer.write(f"{prefix}{field_name}: ", green=True, bold=True)
+            file.write(colored(f"{prefix}{field_name}: ", "green", attrs=["bold"]))
             if field.value is not None:
-                terminal_writer.write(str(field.value))
-            terminal_writer.write(os.linesep)
+                file.write(str(field.value))
+            file.write(os.linesep)
             for subfield in field.subfields:
-                self._pretty_print_field(subfield, field.get_field(subfield), terminal_writer,
+                self._pretty_print_field(subfield, field.get_field(subfield), file,
                                          indent=indent + 1)
         else:
-            terminal_writer.write(f"{prefix}{field_name}: ", green=True, bold=True)
-            terminal_writer.write(f"{field}{os.linesep}")
+            file.write(colored(f"{prefix}{field_name}: ", "green", attrs=["bold"]))
+            file.write(f"{field}{os.linesep}")
 
     def _get_possible_layer_prefixes(self):
         """Gets the possible prefixes for a field under this layer.

src/pyshark/packet/layers/json_layer.py

@@ -1,7 +1,7 @@
 import os
+import io
 
-import py
-
+from pyshark.packet.common import colored
 from pyshark.packet.fields import LayerField
 from pyshark.packet.fields import LayerFieldsContainer
 from pyshark.packet.layers.base import BaseLayer
@@ -79,12 +79,12 @@ def has_field(self, dotted_name) -> bool:
                 return False
         return True
 
-    def _pretty_print_layer_fields(self, terminal_writer: py.io.TerminalWriter):
+    def _pretty_print_layer_fields(self, file: io.IOBase):
         for field_line in self._get_all_field_lines():
             if ':' in field_line:
                 field_name, field_line = field_line.split(':', 1)
-                terminal_writer.write(field_name + ':', green=True, bold=True)
-            terminal_writer.write(field_line, bold=True)
+                file.write(colored(field_name + ':', "green", ["bold"]))
+            file.write(colored(field_line, attrs=["bold"]))
 
     def _get_all_field_lines(self):
         """Returns all lines that represent the fields of the layer (both their names and values)."""

src/pyshark/packet/layers/xml_layer.py

@@ -1,8 +1,8 @@
 import os
 import typing
+import io
 
-import py
-
+from pyshark.packet.common import colored
 from pyshark.packet.fields import LayerField, LayerFieldsContainer
 from pyshark.packet.layers import base
 
@@ -96,12 +96,12 @@ def _sanitize_field_name(self, field_name):
         field_name = field_name.replace(self._field_prefix, '')
         return field_name.replace('.', '_').replace('-', '_').lower()
 
-    def _pretty_print_layer_fields(self, terminal_writer: py.io.TerminalWriter):
+    def _pretty_print_layer_fields(self, file: io.IOBase):
         for field_line in self._get_all_field_lines():
             if ':' in field_line:
                 field_name, field_line = field_line.split(':', 1)
-                terminal_writer.write(field_name + ':', green=True, bold=True)
-            terminal_writer.write(field_line, bold=True)
+                file.write(colored(field_name + ':', "green", attrs=["bold"]))
+            file.write(colored(field_line, attrs=["bold"]))
 
     def _get_all_fields_with_alternates(self):
         all_fields = list(self._all_fields.values())

src/setup.py

@@ -9,7 +9,7 @@
     version="0.5.2",
     packages=find_packages(),
     package_data={'': ['*.ini', '*.pcapng']},
-    install_requires=['lxml', 'py', 'packaging', 'appdirs'],
+    install_requires=['lxml', 'termcolor', 'packaging', 'appdirs'],
     tests_require=['pytest'],
     url="https://github.com/KimiNewt/pyshark",
     license="MIT",

src/tox.ini

@@ -4,7 +4,7 @@ envlist = py{35,36,37,38,39,310}
 [testenv]
 deps =
     appdirs
-    py
+    termcolor
     pytest
     mock
     lxml