add the 'unicode' kwarg to number_to_si; use ascii in SI_PREFIX_MAP

MSLNZ · Sep 14, 2022 · 70e1bc8 · 70e1bc8
1 parent 04efc29
commit 70e1bc8
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Showing 3 changed files with 15 additions and 6 deletions.
diff --git a/msl/qt/constants.py b/msl/qt/constants.py
@@ -6,5 +6,5 @@
 HOME_DIR = os.path.join(os.path.expanduser('~'), '.msl')
 """:class:`str`: The default ``$HOME`` directory where all files used by the package are located."""
 
-SI_PREFIX_MAP = {i: prefix for i, prefix in enumerate('yzafpn\u00b5m kMGTPEZY', start=-8)}
+SI_PREFIX_MAP = {i: prefix for i, prefix in enumerate('yzafpnum kMGTPEZY', start=-8)}
 """:class:`dict`: The SI prefixes used to form multiples of :math:`10^{3n}, n=` -8 .. 8"""
diff --git a/msl/qt/convert.py b/msl/qt/convert.py
@@ -13,6 +13,7 @@
 )
 
 from .constants import SI_PREFIX_MAP
+from .characters import MICRO
 from . import (
     Qt,
     QtGui,
@@ -189,7 +190,7 @@ def ensure_255(value):
         return QtGui.QColor(*tuple(ensure_255(v) for v in args))
 
 
-def number_to_si(number):
+def number_to_si(number, unicode=True):
     """Convert a number to be represented with an SI prefix.
 
     The hecto (h), deka (da), deci (d) and centi (c) prefixes are not used.
@@ -198,6 +199,8 @@ def number_to_si(number):
     ----------
     number : :class:`int` or :class:`float`
         The number to convert.
+    unicode : :class:`bool`, optional
+        Whether to use the unicode \u00B5 symbol for micro.
 
     Returns
     -------
@@ -224,7 +227,11 @@ def number_to_si(number):
         return number, ''
     if n > 8 or n < -8:
         raise ValueError(f'The number {number} cannot be expressed with an SI prefix')
-    return number * 10 ** (-3 * n), SI_PREFIX_MAP[n]
+    if unicode and n == -2:
+        si = MICRO
+    else:
+        si = SI_PREFIX_MAP[n]
+    return number * 10 ** (-3 * n), si
 
 
 def si_to_number(string):
@@ -259,8 +266,8 @@ def si_to_number(string):
         return float(string_)
 
     prefix = string_[-1]
-    if prefix == 'u':
-        prefix = '\u00b5'
+    if prefix == MICRO:
+        prefix = 'u'
     for n, value in SI_PREFIX_MAP.items():
         if prefix == value:
             return float(string_[:-1]) * 10 ** (3 * n)

diff --git a/tests/test_convert.py b/tests/test_convert.py
@@ -12,6 +12,7 @@
     Qt,
     convert,
     binding,
+    characters
 )
 
 
@@ -402,7 +403,8 @@ def check(args, number, string):
     check(convert.number_to_si(-12.3e-10), -1.23, 'n')
     check(convert.number_to_si(1.23e-8), 12.3, 'n')
     check(convert.number_to_si(-0.123e-7), -12.3, 'n')
-    check(convert.number_to_si(0.123e-5), 1.23, '\u00b5')
+    check(convert.number_to_si(0.123e-5), 1.23, characters.MICRO)
+    check(convert.number_to_si(0.123e-5, unicode=False), 1.23, 'u')
     check(convert.number_to_si(-0.0123), -12.3, 'm')
     check(convert.number_to_si(123.4), 123.4, '')
     check(convert.number_to_si(0), 0, '')