MicroPythonOS · bitcoin3us · Mar 27, 2026 · Mar 27, 2026
diff --git a/internal_filesystem/builtin/apps/com.micropythonos.settings/assets/settings.py b/internal_filesystem/builtin/apps/com.micropythonos.settings/assets/settings.py
@@ -1,6 +1,6 @@
 import lvgl as lv
 
-from mpos import Activity, Intent, AppearanceManager, AppManager, SettingActivity, SettingsActivity, TimeZone
+from mpos import Activity, Intent, AppearanceManager, AppManager, NumberFormat, SettingActivity, SettingsActivity, TimeZone
 
 from bootloader import ResetIntoBootloader
 from calibrate_imu import CalibrateIMUActivity
@@ -82,6 +82,7 @@ def getIntent(self):
             {"title": "Light/Dark Theme", "key": "theme_light_dark", "ui": "radiobuttons", "ui_options":  [("Light", "light"), ("Dark", "dark")], "changed_callback": self.theme_changed},
             {"title": "Theme Color", "key": "theme_primary_color", "placeholder": "HTML hex color, like: EC048C", "ui": "dropdown", "ui_options": theme_colors, "changed_callback": self.theme_changed, "default_value": AppearanceManager.DEFAULT_PRIMARY_COLOR},
             {"title": "Timezone", "key": "timezone", "ui": "dropdown", "ui_options": [(tz, tz) for tz in TimeZone.get_timezones()], "changed_callback": lambda *args: TimeZone.refresh_timezone_preference()},
+            {"title": "Number Format", "key": "number_format", "ui": "dropdown", "ui_options": NumberFormat.get_format_options(), "changed_callback": lambda *args: NumberFormat.refresh_preference(), "default_value": "comma_dot"},
             # Advanced settings, alphabetically:
             {"title": "Auto Start App", "key": "auto_start_app", "ui": "radiobuttons", "ui_options":  [(app.name, app.fullname) for app in AppManager.get_app_list()]},
             {"title": "Check IMU Calibration", "key": "check_imu_calibration", "ui": "activity", "activity_class": CheckIMUCalibrationActivity},

diff --git a/internal_filesystem/lib/mpos/__init__.py b/internal_filesystem/lib/mpos/__init__.py
@@ -14,12 +14,16 @@
 from .camera_manager import CameraManager
 from .sensor_manager import SensorManager
 from .time_zone import TimeZone
+from .number_format import NumberFormat
 from .device_info import DeviceInfo
 from .build_info import BuildInfo
 
 # Battery manager (imported early for UI dependencies)
 from .battery_manager import BatteryManager
-from .webserver.webserver import WebServer
+try:
+    from .webserver.webserver import WebServer
+except ImportError:
+    WebServer = None  # _webrepl not available on desktop/Unix builds
 
 # Common activities
 from .app.activities.chooser import ChooserActivity

diff --git a/internal_filesystem/lib/mpos/number_format.py b/internal_filesystem/lib/mpos/number_format.py
@@ -0,0 +1,111 @@
+from . import config
+
+
+NUMBER_FORMAT_MAP = {
+    "comma_dot":   (".", ","),   # 1,234.56  US/UK
+    "dot_comma":   (",", "."),   # 1.234,56  Europe
+    "space_comma": (",", " "),   # 1 234,56  French
+    "apos_dot":    (".", "'"),   # 1'234.56  Swiss
+    "under_dot":   (".", "_"),   # 1_234.56  Tech
+    "none_dot":    (".", ""),    # 1234.56   No thousands
+    "none_comma":  (",", ""),    # 1234,56   No thousands
+}
+
+DEFAULT_FORMAT = "comma_dot"
+
+
+class NumberFormat:
+    """Number formatting utility using the system number format preference."""
+
+    number_format_preference = None
+
+    @staticmethod
+    def refresh_preference():
+        """Refresh the number format preference from SharedPreferences."""
+        NumberFormat.number_format_preference = config.SharedPreferences(
+            "com.micropythonos.settings"
+        ).get_string("number_format")
+        if not NumberFormat.number_format_preference:
+            NumberFormat.number_format_preference = DEFAULT_FORMAT
+
+    @staticmethod
+    def get_separators():
+        """Return (decimal_sep, thousands_sep) for the current preference."""
+        if NumberFormat.number_format_preference is None:
+            NumberFormat.refresh_preference()
+        return NUMBER_FORMAT_MAP.get(
+            NumberFormat.number_format_preference,
+            NUMBER_FORMAT_MAP[DEFAULT_FORMAT],
+        )
+
+    @staticmethod
+    def format_number(value, decimals=None):
+        """Format a number using the current number format preference.
+
+        Args:
+            value: int or float to format.
+            decimals: number of decimal places (None = auto for ints, strip trailing zeros for floats).
+
+        Returns:
+            Formatted string.
+        """
+        dec_sep, thou_sep = NumberFormat.get_separators()
+
+        if isinstance(value, int) and decimals is None:
+            negative = value < 0
+            s = str(abs(value))
+            s = _insert_thousands(s, thou_sep)
+            return ("-" + s) if negative else s
+
+        # Float formatting
+        if decimals is None:
+            decimals = 2
+        s = "{:.{}f}".format(float(value), decimals)
+
+        negative = s.startswith("-")
+        if negative:
+            s = s[1:]
+
+        # Split on the Python decimal point
+        if "." in s:
+            int_part, frac_part = s.split(".")
+            # Strip trailing zeros from fractional part
+            frac_part = frac_part.rstrip("0")
+        else:
+            int_part = s
+            frac_part = ""
+
+        int_part = _insert_thousands(int_part, thou_sep)
+
+        if frac_part:
+            result = int_part + dec_sep + frac_part
+        else:
+            result = int_part
+
+        return ("-" + result) if negative else result
+
+    @staticmethod
+    def get_format_options():
+        """Return a list of (label, key) tuples for the settings dropdown."""
+        return [
+            ("1,234.56 (US/UK)", "comma_dot"),
+            ("1.234,56 (Europe)", "dot_comma"),
+            ("1 234,56 (French)", "space_comma"),
+            ("1'234.56 (Swiss)", "apos_dot"),
+            ("1_234.56 (Tech)", "under_dot"),
+            ("1234.56 (No separator)", "none_dot"),
+            ("1234,56 (No separator)", "none_comma"),
+        ]
+
+
+def _insert_thousands(int_str, separator):
+    """Insert thousands separator into an integer string."""
+    if not separator or len(int_str) <= 3:
+        return int_str
+    parts = []
+    while len(int_str) > 3:
+        parts.append(int_str[-3:])
+        int_str = int_str[:-3]
+    parts.append(int_str)
+    parts.reverse()
+    return separator.join(parts)
diff --git a/tests/test_number_format.py b/tests/test_number_format.py
@@ -0,0 +1,82 @@
+import unittest
+from mpos.number_format import NumberFormat, NUMBER_FORMAT_MAP, DEFAULT_FORMAT
+
+
+class TestNumberFormat(unittest.TestCase):
+
+    def setUp(self):
+        NumberFormat.number_format_preference = DEFAULT_FORMAT
+
+    def test_default_is_us_format(self):
+        self.assertEqual(NumberFormat.get_separators(), (".", ","))
+
+    def test_format_int_default(self):
+        self.assertEqual(NumberFormat.format_number(1234), "1,234")
+        self.assertEqual(NumberFormat.format_number(0), "0")
+        self.assertEqual(NumberFormat.format_number(999), "999")
+        self.assertEqual(NumberFormat.format_number(1000), "1,000")
+        self.assertEqual(NumberFormat.format_number(1234567), "1,234,567")
+
+    def test_format_negative_int(self):
+        self.assertEqual(NumberFormat.format_number(-1234), "-1,234")
+        self.assertEqual(NumberFormat.format_number(-5), "-5")
+
+    def test_format_float_default(self):
+        self.assertEqual(NumberFormat.format_number(1234.56, 2), "1,234.56")
+        self.assertEqual(NumberFormat.format_number(1234.50, 2), "1,234.5")
+        self.assertEqual(NumberFormat.format_number(1234.00, 2), "1,234")
+        self.assertEqual(NumberFormat.format_number(0.5, 2), "0.5")
+
+    def test_format_europe(self):
+        NumberFormat.number_format_preference = "dot_comma"
+        self.assertEqual(NumberFormat.format_number(1234), "1.234")
+        self.assertEqual(NumberFormat.format_number(1234.56, 2), "1.234,56")
+
+    def test_format_french(self):
+        NumberFormat.number_format_preference = "space_comma"
+        self.assertEqual(NumberFormat.format_number(1234), "1 234")
+        self.assertEqual(NumberFormat.format_number(1234.56, 2), "1 234,56")
+
+    def test_format_swiss(self):
+        NumberFormat.number_format_preference = "apos_dot"
+        self.assertEqual(NumberFormat.format_number(1234), "1'234")
+        self.assertEqual(NumberFormat.format_number(1234.56, 2), "1'234.56")
+
+    def test_format_tech(self):
+        NumberFormat.number_format_preference = "under_dot"
+        self.assertEqual(NumberFormat.format_number(1234), "1_234")
+        self.assertEqual(NumberFormat.format_number(1234.56, 2), "1_234.56")
+
+    def test_format_no_thousands_dot(self):
+        NumberFormat.number_format_preference = "none_dot"
+        self.assertEqual(NumberFormat.format_number(1234567), "1234567")
+        self.assertEqual(NumberFormat.format_number(1234.56, 2), "1234.56")
+
+    def test_format_no_thousands_comma(self):
+        NumberFormat.number_format_preference = "none_comma"
+        self.assertEqual(NumberFormat.format_number(1234567), "1234567")
+        self.assertEqual(NumberFormat.format_number(1234.56, 2), "1234,56")
+
+    def test_strip_trailing_zeros(self):
+        NumberFormat.number_format_preference = DEFAULT_FORMAT
+        self.assertEqual(NumberFormat.format_number(1.10, 2), "1.1")
+        self.assertEqual(NumberFormat.format_number(1.00, 2), "1")
+        self.assertEqual(NumberFormat.format_number(1.00, 8), "1")
+
+    def test_large_number(self):
+        self.assertEqual(NumberFormat.format_number(100000000), "100,000,000")
+
+    def test_get_format_options_returns_list(self):
+        options = NumberFormat.get_format_options()
+        self.assertIsInstance(options, list)
+        self.assertTrue(len(options) == len(NUMBER_FORMAT_MAP))
+        for label, key in options:
+            self.assertIn(key, NUMBER_FORMAT_MAP)
+
+    def test_unknown_preference_falls_back_to_default(self):
+        NumberFormat.number_format_preference = "nonexistent"
+        self.assertEqual(NumberFormat.get_separators(), (".", ","))
+
+
+if __name__ == "__main__":
+    unittest.main()