move the type difference declaration to pycompat

pysnooper/pycompat.py

@@ -5,6 +5,7 @@
 import abc
 import os
 import inspect
+import sys
 
 if hasattr(abc, 'ABC'):
     ABC = abc.ABC
@@ -42,3 +43,12 @@ try:
     iscoroutinefunction = inspect.iscoroutinefunction
 except AttributeError:
     iscoroutinefunction = lambda whatever: False # Lolz
+
+PY3 = sys.version_info[0] == 3
+
+if PY3:
+    string_types = str,
+    text_type = str
+else:
+    string_types = basestring,
+    text_type = unicode

pysnooper/tracer.py

@@ -92,7 +92,7 @@ def get_source_from_frame(frame):
             if match:
                 encoding = match.group(1).decode('ascii')
                 break
-        source = [utils.text_type(sline, encoding, 'replace') for sline in
+        source = [pycompat.text_type(sline, encoding, 'replace') for sline in
                   source]
 
     source_cache[cache_key] = source
@@ -126,7 +126,7 @@ def get_write_function(output, overwrite):
 
 class FileWriter(object):
     def __init__(self, path, overwrite):
-        self.path = utils.text_type(path)
+        self.path = pycompat.text_type(path)
         self.overwrite = overwrite
 
     def write(self, s):

pysnooper/utils.py

@@ -4,18 +4,7 @@
 import abc
 
 import sys
-from .pycompat import ABC
-
-PY2 = sys.version_info[0] == 2
-PY3 = sys.version_info[0] == 3
-
-if PY3:
-    string_types = str,
-    text_type = str
-else:
-    string_types = basestring,
-    text_type = unicode
-
+from .pycompat import ABC, string_types
 
 MAX_VARIABLE_LENGTH = 100
 MAX_EXCEPTION_LENGTH = 200