util: small clean-up for format_satoshis

electrum/gui/kivy/main_window.py

@@ -293,7 +293,7 @@ class ElectrumWindow(App):
         if rate.is_nan():
             return ''
         satoshis = int(pow(10,8) * Decimal(fiat_amount) / Decimal(rate))
-        return format_satoshis_plain(satoshis, self.decimal_point())
+        return format_satoshis_plain(satoshis, decimal_point=self.decimal_point())
 
     def get_amount(self, amount_str):
         a, u = amount_str.split()
@@ -909,17 +909,23 @@ class ElectrumWindow(App):
         amount = tx.output_value()
         __, x_fee_amount = run_hook('get_tx_extra_fee', self.wallet, tx) or (None, 0)
         amount_after_all_fees = amount - x_fee_amount
-        return format_satoshis_plain(amount_after_all_fees, self.decimal_point())
+        return format_satoshis_plain(amount_after_all_fees, decimal_point=self.decimal_point())
 
     def format_amount(self, x, is_diff=False, whitespaces=False):
-        return format_satoshis(x, 0, self.decimal_point(), is_diff=is_diff, whitespaces=whitespaces)
+        return format_satoshis(
+            x,
+            num_zeros=0,
+            decimal_point=self.decimal_point(),
+            is_diff=is_diff,
+            whitespaces=whitespaces,
+        )
 
     def format_amount_and_units(self, x) -> str:
         if x is None:
             return 'none'
         if x == '!':
             return 'max'
-        return format_satoshis_plain(x, self.decimal_point()) + ' ' + self.base_unit
+        return format_satoshis_plain(x, decimal_point=self.decimal_point()) + ' ' + self.base_unit
 
     def format_fee_rate(self, fee_rate):
         # fee_rate is in sat/kB

electrum/gui/qt/amountedit.py

@@ -110,7 +110,7 @@ class BTCAmountEdit(AmountEdit):
         if amount is None:
             self.setText(" ") # Space forces repaint in case units changed
         else:
-            self.setText(format_satoshis_plain(amount, self.decimal_point()))
+            self.setText(format_satoshis_plain(amount, decimal_point=self.decimal_point()))
 
 
 class FeerateEdit(BTCAmountEdit):

electrum/gui/qt/main_window.py

@@ -54,8 +54,7 @@ from electrum import (keystore, ecc, constants, util, bitcoin, commands,
 from electrum.bitcoin import COIN, is_address
 from electrum.plugin import run_hook, BasePlugin
 from electrum.i18n import _
-from electrum.util import (format_time, format_satoshis, format_fee_satoshis,
-                           format_satoshis_plain,
+from electrum.util import (format_time,
                            UserCancelled, profiler,
                            bh2u, bfh, InvalidPassword,
                            UserFacingException,

electrum/simple_config.py

@@ -614,7 +614,13 @@ class SimpleConfig(Logger):
                 pass
 
     def format_amount(self, x, is_diff=False, whitespaces=False):
-        return format_satoshis(x, self.num_zeros, self.decimal_point, is_diff=is_diff, whitespaces=whitespaces)
+        return format_satoshis(
+            x,
+            num_zeros=self.num_zeros,
+            decimal_point=self.decimal_point,
+            is_diff=is_diff,
+            whitespaces=whitespaces,
+        )
 
     def format_amount_and_units(self, amount):
         return self.format_amount(amount) + ' '+ self.get_base_unit()

electrum/tests/test_util.py

@@ -1,7 +1,8 @@
 from decimal import Decimal
 
 from electrum.util import (format_satoshis, format_fee_satoshis, parse_URI,
-                           is_hash256_str, chunks, is_ip_address, list_enabled_bits)
+                           is_hash256_str, chunks, is_ip_address, list_enabled_bits,
+                           format_satoshis_plain)
 
 from . import ElectrumTestCase
 
@@ -14,6 +15,12 @@ class TestUtil(ElectrumTestCase):
     def test_format_satoshis_negative(self):
         self.assertEqual("-0.00001234", format_satoshis(-1234))
 
+    def test_format_satoshis_to_mbtc(self):
+        self.assertEqual("0.01234", format_satoshis(1234, decimal_point=5))
+
+    def test_format_satoshis_decimal(self):
+        self.assertEqual("0.00001234", format_satoshis(Decimal(1234)))
+
     def test_format_fee_float(self):
         self.assertEqual("1.7", format_fee_satoshis(1700/1000))
 
@@ -45,6 +52,15 @@ class TestUtil(ElectrumTestCase):
     def test_format_satoshis_diff_negative(self):
         self.assertEqual("-0.00001234", format_satoshis(-1234, is_diff=True))
 
+    def test_format_satoshis_plain(self):
+        self.assertEqual("0.00001234", format_satoshis_plain(1234))
+
+    def test_format_satoshis_plain_decimal(self):
+        self.assertEqual("0.00001234", format_satoshis_plain(Decimal(1234)))
+
+    def test_format_satoshis_plain_to_mbtc(self):
+        self.assertEqual("0.01234", format_satoshis_plain(1234, decimal_point=5))
+
     def _do_test_parse_URI(self, uri, expected):
         result = parse_URI(uri)
         self.assertEqual(expected, result)

electrum/util.py

@@ -582,7 +582,7 @@ def chunks(items, size: int):
         yield items[i: i + size]
 
 
-def format_satoshis_plain(x, decimal_point = 8) -> str:
+def format_satoshis_plain(x, *, decimal_point=8) -> str:
     """Display a satoshi amount scaled.  Always uses a '.' as a decimal
     point and has no thousands separator"""
     if x == '!':
@@ -594,7 +594,15 @@ def format_satoshis_plain(x, decimal_point = 8) -> str:
 DECIMAL_POINT = localeconv()['decimal_point']  # type: str
 
 
-def format_satoshis(x, num_zeros=0, decimal_point=8, precision=None, is_diff=False, whitespaces=False) -> str:
+def format_satoshis(
+        x,  # in satoshis
+        *,
+        num_zeros=0,
+        decimal_point=8,
+        precision=None,
+        is_diff=False,
+        whitespaces=False,
+) -> str:
     if x is None:
         return 'unknown'
     if x == '!':