refactor: rename isfloat to is_number, in a separate validators.py folder

Author: bobleesj

src/diffpy/utils/parsers/loaddata.py

@@ -17,6 +17,8 @@
 
 import numpy
 
+from diffpy.utils import validators
+
 
 def loadData(filename, minrows=10, headers=False, hdel="=", hignore=None, **kwargs):
     """Find and load data from a text file.
@@ -139,7 +141,7 @@ def countcolumnsvalues(line):
                     name = hpair[0]
                     value = hpair[1]
                     # check if data value should be stored as float
-                    if isfloat(hpair[1]):
+                    if validators.is_number(hpair[1]):
                         value = float(hpair[1])
                     hdata.update({name: value})
             # continue search for the start of datablock
@@ -331,16 +333,3 @@ def _findDataBlocks(self):
             self.headers.append(header)
             self.datasets.append(data)
         return
-
-
-# End of class TextDataLoader
-
-
-def isfloat(s):
-    """True if s is convertible to float."""
-    try:
-        float(s)
-        return True
-    except ValueError:
-        pass
-    return False

src/diffpy/utils/validators.py

@@ -0,0 +1,45 @@
+def is_number(string):
+    """
+    Check if the provided string can be converted to a float.
+
+    Parameters
+    ----------
+    string : str
+        The string to evaluate for numeric conversion.
+
+    Returns
+    -------
+    bool
+        The boolean whether `string` can be successfully converted to float.
+
+    Examples
+    --------
+    >>> is_number("3.14")
+    True
+
+    >>> is_number("-1.23")
+    True
+
+    >>> is_number("007")
+    True
+
+    >>> is_number("five")
+    False
+
+    >>> is_number("3.14.15")
+    False
+
+    >>> is_number("NaN")
+    True
+    
+    >>> is_number("Infinity")
+    True
+    
+    >>> is_number("Inf")
+    True
+    """
+    try:
+        float(string)
+        return True
+    except ValueError:
+        return False

tests/test_validators.py

@@ -0,0 +1,22 @@
+from diffpy.utils.validators import is_number
+import pytest
+
+@pytest.mark.parametrize("input,expected", [
+    ("3.14", True),         # Standard float
+    ("2", True),            # Integer
+    ("-100", True),         # Negative integer
+    ("-3.14", True),        # Negative float
+    ("0", True),            # Zero
+    ("4.5e-1", True),       # Scientific notation
+    ("abc", False),         # Non-numeric string
+    ("", False),            # Empty string
+    ("3.14.15", False),     # Multiple dots
+    ("2+3", False),         # Arithmetic expression
+    ("NaN", True),          # Not a Number (special float value)
+    ("Infinity", True),     # Positive infinity
+    ("-Infinity", True),    # Negative infinity
+    ("Inf", True),          # Positive infinity
+    ("-Inf", True),         # Negative infinity
+])
+def test_is_number(input, expected):
+    assert is_number(input) == expected