nym: Expand usability

This expands the number of translations and enables the
caller to (optionally) override the default translations.

tests/test_strutil_nym.py

@@ -7,6 +7,8 @@
 
 def test_identity():
     assert nym('abc') == 'abc'
+    assert nym('') == ''
+    assert nym(None) is None
 
 
 def test_spaces():
@@ -19,3 +21,28 @@ def test_tabs():
 
 def test_lowercase():
     assert nym('aBcDeF') == 'abcdef'
+
+
+def test_underscores():
+    assert nym('a.b') == 'a_b'
+    assert nym('a-b+c') == 'a_b_c'
+
+
+def test_removes():
+    assert nym('a(b)[c]{d}/e=f') == 'abcdef'
+
+
+def test_non_null():
+    # If we pass in a string, we should get _something_ back,
+    # even if all characters would otherwise be removed
+    assert nym('()')
+
+
+def test_integer():
+    assert nym(1) == '1'
+
+
+def test_params():
+    assert nym('1', remove='1') == '_'
+    assert nym('12', underscore='1') == '_2'
+    assert nym('123', underscore='1', remove='3') == '_2'

toolchest/strutil.py

@@ -32,7 +32,7 @@ def regex_match(pattern, arg):
     return False
 
 
-def nym(arg):
+def nym(arg, underscore='+-. !?;:\'",\t', remove='()[]{}?<>/='):
     '''
     This is for allowing case and quote flexibility for strings when
     searching dictionaries or other data sets based on user input (esp.
@@ -44,10 +44,15 @@ def nym(arg):
 
     Parameters:
         arg (string): A string to create the nym for
+        underscore (string): A set of characters to replace with underscores
+        remove (string): A set of characters to remove from the return value
 
     Returns:
-        ret (string): A lower-case string with whitespace swapped to _
+        ret (string): A lower-case string with characters translated
+                      or removed.
     '''
-    ret = arg.lower().replace(' ', '_')
-    ret = ret.replace('\t', '_')
+    if (ret := arg) not in ('', None):
+        tr = str.maketrans(underscore, '_' * len(underscore), remove)
+        ret = str(arg).lower().translate(tr) or '_'
+
     return ret