diff --git a/doc/source/functions.rst b/doc/source/functions.rst
index 8ea67a69..fdaa4c78 100644
--- a/doc/source/functions.rst
+++ b/doc/source/functions.rst
@@ -65,6 +65,8 @@ SI Unit Conversion Functions
.. autofunction:: pyqtgraph.siEval
+.. autofunction:: pyqtgraph.siParse
+
Image Preparation Functions
---------------------------
@@ -100,5 +102,3 @@ Miscellaneous Functions
.. autofunction:: pyqtgraph.systemInfo
.. autofunction:: pyqtgraph.exit
-
-
diff --git a/examples/SpinBox.py b/examples/SpinBox.py
index f7023037..88366cdf 100644
--- a/examples/SpinBox.py
+++ b/examples/SpinBox.py
@@ -31,6 +31,8 @@ spins = [
pg.SpinBox(value=1.0, suffix='V', siPrefix=True, dec=True, step=0.5, minStep=0.01)),
("Float with SI-prefixed units,
dec step=1.0, minStep=0.001",
pg.SpinBox(value=1.0, suffix='V', siPrefix=True, dec=True, step=1.0, minStep=0.001)),
+ ("Float with SI prefix but no suffix",
+ pg.SpinBox(value=1e9, siPrefix=True)),
("Float with custom formatting",
pg.SpinBox(value=23.07, format='${value:0.02f}',
regex='\$?(?P(-?\d+(\.\d+)?)|(-?\.\d+))$')),
diff --git a/pyqtgraph/functions.py b/pyqtgraph/functions.py
index 037f0f51..994520ba 100644
--- a/pyqtgraph/functions.py
+++ b/pyqtgraph/functions.py
@@ -119,10 +119,28 @@ def siFormat(x, precision=3, suffix='', space=True, error=None, minVal=1e-25, al
def siParse(s, regex=FLOAT_REGEX, suffix=None):
"""Convert a value written in SI notation to a tuple (number, si_prefix, suffix).
-
+
Example::
-
- siParse('100 μV") # returns ('100', 'μ', 'V')
+
+ siParse('100 µV") # returns ('100', 'µ', 'V')
+
+ Note that in the above example, the µ symbol is the "micro sign" (UTF-8
+ 0xC2B5), as opposed to the Greek letter mu (UTF-8 0xCEBC).
+
+ Parameters
+ ----------
+ s : str
+ The string to parse.
+ regex : re.Pattern, optional
+ Compiled regular expression object for parsing. The default is a
+ general-purpose regex for parsing floating point expressions,
+ potentially containing an SI prefix and a suffix.
+ suffix : str, optional
+ Suffix to check for in ``s``. The default (None) indicates there may or
+ may not be a suffix contained in the string and it is returned if
+ found. An empty string ``""`` is handled differently: if the string
+ contains a suffix, it is discarded. This enables interpreting
+ characters following the numerical value as an SI prefix.
"""
s = asUnicode(s)
s = s.strip()
@@ -130,15 +148,20 @@ def siParse(s, regex=FLOAT_REGEX, suffix=None):
if s[-len(suffix):] != suffix:
raise ValueError("String '%s' does not have the expected suffix '%s'" % (s, suffix))
s = s[:-len(suffix)] + 'X' # add a fake suffix so the regex still picks up the si prefix
-
+
+ # special case: discard any extra characters if suffix is explicitly empty
+ if suffix == "":
+ s += 'X'
+
m = regex.match(s)
if m is None:
raise ValueError('Cannot parse number "%s"' % s)
+
try:
sip = m.group('siPrefix')
except IndexError:
sip = ''
-
+
if suffix is None:
try:
suf = m.group('suffix')
@@ -146,8 +169,8 @@ def siParse(s, regex=FLOAT_REGEX, suffix=None):
suf = ''
else:
suf = suffix
-
- return m.group('number'), '' if sip is None else sip, '' if suf is None else suf
+
+ return m.group('number'), '' if sip is None else sip, '' if suf is None else suf
def siEval(s, typ=float, regex=FLOAT_REGEX, suffix=None):
diff --git a/pyqtgraph/tests/test_functions.py b/pyqtgraph/tests/test_functions.py
index e7849809..cc7f5a89 100644
--- a/pyqtgraph/tests/test_functions.py
+++ b/pyqtgraph/tests/test_functions.py
@@ -423,6 +423,30 @@ def test_eq():
assert eq(set(range(10)), set(range(10)))
assert not eq(set(range(10)), set(range(9)))
-
-if __name__ == '__main__':
- test_interpolateArray()
+
+@pytest.mark.parametrize("s,suffix,expected", [
+ # usual cases
+ ("100 uV", "V", ("100", "u", "V")),
+ ("100 µV", "V", ("100", "µ", "V")),
+ ("4.2 nV", None, ("4.2", "n", "V")),
+ ("1.2 m", "m", ("1.2", "", "m")),
+ ("1.2 m", None, ("1.2", "", "m")),
+ ("5.0e9", None, ("5.0e9", "", "")),
+ ("2 units", "units", ("2", "", "units")),
+ # siPrefix with explicit empty suffix
+ ("1.2 m", "", ("1.2", "m", "")),
+ ("5.0e-9 M", "", ("5.0e-9", "M", "")),
+ # weirder cases that should return the reasonable thing
+ ("4.2 nV", "nV", ("4.2", "", "nV")),
+ ("4.2 nV", "", ("4.2", "n", "")),
+ ("1.2 j", "", ("1.2", "", "")),
+ ("1.2 j", None, ("1.2", "", "j")),
+ # expected error cases
+ ("100 uV", "v", ValueError),
+])
+def test_siParse(s, suffix, expected):
+ if isinstance(expected, tuple):
+ assert pg.siParse(s, suffix=suffix) == expected
+ else:
+ with pytest.raises(expected):
+ pg.siParse(s, suffix=suffix)
diff --git a/pyqtgraph/widgets/SpinBox.py b/pyqtgraph/widgets/SpinBox.py
index b6acc8d7..108a32c1 100644
--- a/pyqtgraph/widgets/SpinBox.py
+++ b/pyqtgraph/widgets/SpinBox.py
@@ -132,8 +132,10 @@ class SpinBox(QtGui.QAbstractSpinBox):
siPrefix (bool) If True, then an SI prefix is automatically prepended
to the units and the value is scaled accordingly. For example,
if value=0.003 and suffix='V', then the SpinBox will display
- "300 mV" (but a call to SpinBox.value will still return 0.003). Default
- is False.
+ "300 mV" (but a call to SpinBox.value will still return 0.003). In case
+ the value represents a dimensionless quantity that might span many
+ orders of magnitude, such as a Reynold's number, an SI
+ prefix is allowed with no suffix. Default is False.
step (float) The size of a single step. This is used when clicking the up/
down arrows, when rolling the mouse wheel, or when pressing
keyboard arrows while the widget has keyboard focus. Note that
@@ -466,7 +468,7 @@ class SpinBox(QtGui.QAbstractSpinBox):
# format the string
val = self.value()
- if self.opts['siPrefix'] is True and len(self.opts['suffix']) > 0:
+ if self.opts['siPrefix'] is True:
# SI prefix was requested, so scale the value accordingly
if self.val == 0 and prev is not None:
@@ -545,7 +547,7 @@ class SpinBox(QtGui.QAbstractSpinBox):
return False
# check suffix
- if suffix != self.opts['suffix'] or (suffix == '' and siprefix != ''):
+ if suffix != self.opts['suffix']:
return False
# generate value
diff --git a/pyqtgraph/widgets/tests/test_spinbox.py b/pyqtgraph/widgets/tests/test_spinbox.py
index bbef5eaa..19a7bbfa 100644
--- a/pyqtgraph/widgets/tests/test_spinbox.py
+++ b/pyqtgraph/widgets/tests/test_spinbox.py
@@ -23,6 +23,7 @@ def test_SpinBox_defaults():
(1.45, '1.45 PSI', dict(int=False, decimals=6, suffix='PSI', siPrefix=True)),
(1.45e-3, '1.45 mPSI', dict(int=False, decimals=6, suffix='PSI', siPrefix=True)),
(-2500.3427, '$-2500.34', dict(int=False, format='${value:0.02f}')),
+ (1000, '1 k', dict(siPrefix=True, suffix="")),
])
def test_SpinBox_formatting(value, expected_text, opts):
sb = pg.SpinBox(**opts)
@@ -35,10 +36,11 @@ def test_SpinBox_formatting(value, expected_text, opts):
@pytest.mark.parametrize("suffix", ["", "V"])
def test_SpinBox_gui_set_value(suffix):
sb = pg.SpinBox(suffix=suffix)
+
sb.lineEdit().setText('0.1' + suffix)
sb.editingFinishedEvent()
assert sb.value() == 0.1
- if suffix != '':
- sb.lineEdit().setText('0.1 m' + suffix)
- sb.editingFinishedEvent()
- assert sb.value() == 0.1e-3
+
+ sb.lineEdit().setText('0.1 m' + suffix)
+ sb.editingFinishedEvent()
+ assert sb.value() == 0.1e-3