Accept floating-point nan and inf as fnumber

pyparsing · Jan 21, 2024 · e029f0c · e029f0c
1 parent 2a1a8e8
commit e029f0c
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Showing 3 changed files with 20 additions and 6 deletions.
diff --git a/docs/HowToUsePyparsing.rst b/docs/HowToUsePyparsing.rst
@@ -1365,7 +1365,7 @@ Common string and token constants
 
 - ``common.number`` - any numeric expression; parsed tokens are returned as converted by the matched expression
 
-- ``common.fnumber`` - any numeric expression; parsed tokens are converted to float
+- ``common.fnumber`` - any numeric expression; parsed tokens are converted to float (including floating-point nan and inf)
 
 - ``common.identifier`` - a programming identifier (follows Python's syntax convention of leading alpha or "_",
   followed by 0 or more alpha, num, or "_")

diff --git a/pyparsing/common.py b/pyparsing/common.py
@@ -43,13 +43,20 @@ class pyparsing_common:
             ''')
 
         pyparsing_common.fnumber.run_tests('''
-            # any int or real number, returned as float
+            # any numeric expression, returned as float (including floating-point nan and inf)
             100
             -100
             +100
             3.14159
             6.02e23
-            1e-12
+            1E-12
+            0
+            -0
+            NaN
+            nan
+            -NAN
+            inf
+            -Infinity
             ''')
 
         pyparsing_common.hex_integer.run_tests('''
@@ -210,11 +217,11 @@ class pyparsing_common:
     """any numeric expression, returns the corresponding Python type"""
 
     fnumber = (
-        Regex(r"[+-]?\d+\.?\d*([eE][+-]?\d+)?")
+        Regex(r"(?i)[+-]?((\d+\.?\d*(e[+-]?\d+)?)|nan|inf(inity)?)")
         .set_name("fnumber")
         .set_parse_action(convert_to_float)
     )
-    """any int or real number, returned as float"""
+    """any numeric expression, returned as float (including floating-point nan and inf)"""
 
     identifier = Word(identchars, identbodychars).set_name("identifier")
     """typical code identifier (leading alpha or '_', followed by 0 or more alphas, nums, or '_')"""

diff --git a/tests/test_unit.py b/tests/test_unit.py
@@ -6594,7 +6594,14 @@ def testCommonExpressions(self):
                 +100
                 3.14159
                 6.02e23
-                1e-12
+                1E-12
+                0
+                -0
+                NaN
+                nan
+                -NAN
+                inf
+                -Infinity
                 """
             )[0]
             self.assertTrue(success, "error in parsing valid numerics")