Merge pull request spotify#39 from spotify/second_y_axis

Added second axis

HISTORY.rst

@@ -2,6 +2,22 @@
 History
 =======
 
+2.4.0 (2019-02-16)
+------------------
+
+Improvements:
+
+* Added second Y axis plotting.
+* Removed Bokeh loading notification on import (Thanks @canavandl!)
+* Added support for custom Bokeh resource loading (Thanks @canavandl!)
+* Added example for Chart.save() method (Thanks @david30907d!)
+
+Bugfixes:
+
+* Updated documentation for saving and showing svgs.
+* Fixed bug that broke plots with no difference between min and max
+  points. (Thanks for finding @fabioconcina!)
+
 2.3.5 (2018-11-21)
 ------------------
 

README.rst

@@ -4,7 +4,7 @@ Chartify
 |status|  |release|  |python|
 
 .. |status| image:: https://img.shields.io/badge/Status-Beta-blue.svg
-.. |release| image:: https://img.shields.io/badge/Release-2.3.5-blue.svg
+.. |release| image:: https://img.shields.io/badge/Release-2.4.0-blue.svg
 .. |python| image:: https://img.shields.io/badge/Python-3.6-blue.svg
 
 Chartify is a Python library that makes it easy for data scientists to create charts.

chartify/__init__.py

@@ -21,7 +21,7 @@
 
 __author__ = """Chris Halpert"""
 __email__ = '[email protected]'
-__version__ = '2.3.5'
+__version__ = '2.4.0'
 
 _IPYTHON_INSTANCE = False
 

chartify/_core/axes.py

@@ -21,14 +21,59 @@
 import pandas as pd
 import bokeh
 from bokeh.models.tickers import FixedTicker
+from bokeh.models import LinearAxis, LogAxis, DataRange1d
 from math import pi
 
 
-class BaseAxes:
+class YAxisMixin:
+
+    def __init__(self):
+        self._y_axis_index = 0
+        self._y_range = self._chart.figure.y_range
+
+    @property
+    def yaxis_label(self):
+        """Return y-axis label.
+
+        Returns:
+            y-axis label text
+        """
+        return self._chart.figure.yaxis[self._y_axis_index].axis_label
+
+    def set_yaxis_label(self, label):
+        """Set y-axis label text.
+
+        Args:
+            label (string): the text for the y-axis label
+
+        Returns:
+            Current chart object
+        """
+        self._chart.figure.yaxis[self._y_axis_index].axis_label = label
+        return self._chart
+
+    def hide_yaxis(self):
+        """Hide the tick labels, ticks, and axis lines of the y-axis.
+
+        The y-axis label will remain visible, but can be
+        removed with .axes.set_yaxis_label("")
+        """
+        self._chart.figure.yaxis[self._y_axis_index].axis_line_alpha = 0
+        self._chart.figure.yaxis[
+            self._y_axis_index].major_tick_line_color = None
+        self._chart.figure.yaxis[
+            self._y_axis_index].minor_tick_line_color = None
+        self._chart.figure.yaxis[
+            self._y_axis_index].major_label_text_color = None
+        return self._chart
+
+
+class BaseAxes(YAxisMixin):
     """Base class for axes."""
 
     def __init__(self, chart):
         self._chart = chart
+        super(BaseAxes, self).__init__()
         self._initialize_defaults()
 
     @classmethod
@@ -119,27 +164,6 @@ def set_xaxis_label(self, label):
         self._chart.figure.xaxis.axis_label = label
         return self._chart
 
-    @property
-    def yaxis_label(self):
-        """Return y-axis label.
-
-        Returns:
-            y-axis label text
-        """
-        return self._chart.figure.yaxis.axis_label
-
-    def set_yaxis_label(self, label):
-        """Set y-axis label text.
-
-        Args:
-            label (string): the text for the y-axis label
-
-        Returns:
-            Current chart object
-        """
-        self._chart.figure.yaxis.axis_label = label
-        return self._chart
-
     def hide_xaxis(self):
         """Hide the tick labels, ticks, and axis lines of the x-axis.
 
@@ -156,19 +180,6 @@ def hide_xaxis(self):
 
         return self._chart
 
-    def hide_yaxis(self):
-        """Hide the tick labels, ticks, and axis lines of the y-axis.
-
-        The y-axis label will remain visible, but can be
-        removed with .axes.set_yaxis_label("")
-        """
-        self._chart.figure.yaxis.axis_line_alpha = 0
-        self._chart.figure.yaxis.major_tick_line_color = None
-        self._chart.figure.yaxis.minor_tick_line_color = None
-        self._chart.figure.yaxis.major_label_text_color = None
-
-        return self._chart
-
     def set_xaxis_tick_orientation(self, orientation='horizontal'):
         """Change the orientation or the x axis tick labels.
 
@@ -266,6 +277,7 @@ def set_xaxis_tick_format(self, num_format):
 
 
 class NumericalYMixin:
+
     def set_yaxis_range(self, start=None, end=None):
         """Set y-axis range.
 
@@ -276,8 +288,8 @@ def set_yaxis_range(self, start=None, end=None):
         Returns:
             Current chart object
         """
-        self._chart.figure.y_range.end = end
-        self._chart.figure.y_range.start = start
+        self._y_range.end = end
+        self._y_range.start = start
         return self._chart
 
     def set_yaxis_tick_values(self, values):
@@ -289,7 +301,8 @@ def set_yaxis_tick_values(self, values):
         Returns:
             Current chart object
         """
-        self._chart.figure.yaxis.ticker = FixedTicker(ticks=values)
+        self._chart.figure.yaxis[
+            self._y_axis_index].ticker = FixedTicker(ticks=values)
         return self._chart
 
     def set_yaxis_tick_format(self, num_format):
@@ -321,8 +334,8 @@ def set_yaxis_tick_format(self, num_format):
         Returns:
             Current chart object
         """
-        self._chart.figure.yaxis[
-            0].formatter = bokeh.models.NumeralTickFormatter(format=num_format)
+        self._chart.figure.yaxis[self._y_axis_index].formatter = (
+                bokeh.models.NumeralTickFormatter(format=num_format))
         return self._chart
 
 
@@ -572,3 +585,31 @@ class CategoricalXYAxes(BaseAxes, CategoricalXMixin, CategoricalYMixin):
     def __init__(self, chart):
         super(CategoricalXYAxes, self).__init__(chart)
         self._chart.style._apply_settings('categorical_xyaxis')
+
+
+class SecondYNumericalAxis(YAxisMixin, NumericalYMixin):
+    """Axis class for second Y numerical axes."""
+    def __init__(self, chart):
+        self._chart = chart
+        self._y_range_name = 'second_y'
+        self._chart.figure.extra_y_ranges = {
+            self._y_range_name: DataRange1d(bounds='auto')
+        }
+        # Add the appropriate axis type to the figure.
+        axis_class = LinearAxis
+        if self._chart._second_y_axis_type == 'log':
+            axis_class = LogAxis
+        self._chart.figure.add_layout(
+            axis_class(y_range_name=self._y_range_name), 'right')
+
+        self._y_axis_index = 1
+        self._y_range = self._chart.figure.extra_y_ranges[self._y_range_name]
+        self._chart.style._apply_settings('second_y_axis')
+
+
+class SecondAxis:
+    """Class for second axis.
+
+    - Plotting (.plot)
+    - Axes (.axes)
+    """

chartify/_core/chart.py

@@ -36,7 +36,7 @@
 from selenium.webdriver.chrome.options import Options
 
 from chartify._core.style import Style
-from chartify._core.axes import BaseAxes
+from chartify._core.axes import BaseAxes, SecondYNumericalAxis, SecondAxis
 from chartify._core.plot import BasePlot
 from chartify._core.callout import Callout
 from chartify._core.options import options
@@ -57,7 +57,8 @@ def __init__(self,
                  blank_labels=options.get_option('chart.blank_labels'),
                  layout='slide_100%',
                  x_axis_type='linear',
-                 y_axis_type='linear'):
+                 y_axis_type='linear',
+                 second_y_axis=False):
         """Create a chart instance.
 
         Args:
@@ -91,13 +92,23 @@ def __init__(self,
             'linear', 'log', 'datetime', 'categorical', 'density'
         ]
         valid_y_axis_types = ['linear', 'log', 'categorical', 'density']
+        valid_second_y_axis_types = ['linear', 'log']
         if x_axis_type not in valid_x_axis_types:
             raise ValueError('x_axis_type must be one of {options}'.format(
                 options=valid_x_axis_types))
         if y_axis_type not in valid_y_axis_types:
             raise ValueError('y_axis_type must be one of {options}'.format(
                 options=valid_y_axis_types))
 
+        self._second_y_axis_type = None
+        if second_y_axis:
+            self._second_y_axis_type = y_axis_type
+            if self._second_y_axis_type not in valid_second_y_axis_types:
+                raise ValueError(
+                    'second_y_axis can only be used when \
+                    y_axis_type is one of {options}'.format(
+                        options=valid_second_y_axis_types))
+
         self._x_axis_type, self._y_axis_type = x_axis_type, y_axis_type
 
         self._blank_labels = options._get_value(blank_labels)
@@ -110,6 +121,13 @@ def __init__(self,
         self.callout = Callout(self)
         self.axes = BaseAxes._get_axis_class(self._x_axis_type,
                                              self._y_axis_type)(self)
+
+        if self._second_y_axis_type in valid_second_y_axis_types:
+            self.second_axis = SecondAxis()
+            self.second_axis.axes = SecondYNumericalAxis(self)
+            self.second_axis.plot = BasePlot._get_plot_class(
+                self._x_axis_type, self._second_y_axis_type)(
+                    self, self.second_axis.axes._y_range_name)
         self._source = self._add_source_to_figure()
         self._subtitle_glyph = self._add_subtitle_to_figure()
         self.figure.toolbar.logo = None  # Remove bokeh logo from toolbar.
@@ -346,6 +364,8 @@ def show(self, format='html'):
                     Easy to copy+paste into slides.
                     Will render logos.
                     Recommended when the plot is in a finished state.
+
+                - 'svg': Output as SVG.
                 """
         self._set_toolbar_for_format(format)
 
@@ -376,6 +396,8 @@ def save(self, filename, format='html'):
                     Easy to paste into google slides.
                     Recommended when the plot is in a finished state.
                     Will render logos.
+
+                - 'svg': Output as SVG.
         """
         self._set_toolbar_for_format(format)
 

chartify/_core/plot.py

@@ -30,8 +30,9 @@
 class BasePlot:
     """Base for all plot classes."""
 
-    def __init__(self, chart):
+    def __init__(self, chart, y_range_name="default"):
         self._chart = chart
+        self._y_range_name = y_range_name
 
     @staticmethod
     def _axis_format_precision(max_value, min_value):
@@ -115,7 +116,9 @@ def _cannonical_series_name(series_name):
 
     @staticmethod
     def _named_column_data_source(data_frame, series_name):
-        """Ensure consistent naming of column data sources."""
+        """Ensure consistent naming of column data sources.
+        Naming ensures that Chart.data property will populate correctly.
+        """
         cannonical_series_name = BasePlot._cannonical_series_name(series_name)
         return bokeh.models.ColumnDataSource(
             data_frame, name=cannonical_series_name)
@@ -358,7 +361,8 @@ def line(self,
                 line_cap=line_cap,
                 legend=color_value,
                 line_dash=line_dash,
-                alpha=alpha)
+                alpha=alpha,
+                y_range_name=self._y_range_name)
 
         # Set legend defaults if there are multiple series.
         if color_column is not None:
@@ -432,7 +436,8 @@ def scatter(self,
                 legend=color_value,
                 marker=marker,
                 line_color=color,
-                alpha=alpha)
+                alpha=alpha,
+                y_range_name=self._y_range_name)
 
         # Set legend defaults if there are multiple series.
         if color_column is not None:
@@ -514,7 +519,8 @@ def text(self,
                 x_offset=x_offset,
                 angle=angle,
                 angle_units='deg',
-                text_font=text_font)
+                text_font=text_font,
+                y_range_name=self._y_range_name)
         return self._chart
 
     def area(self,
@@ -619,15 +625,17 @@ def area(self,
                     alpha=alpha,
                     source=source,
                     legend=color_value,
-                    color=color)
+                    color=color,
+                    y_range_name=self._y_range_name)
             else:
                 self._chart.figure.patch(
                     x=y_column,
                     y=x_column,
                     alpha=alpha,
                     source=source,
                     legend=color_value,
-                    color=color)
+                    color=color,
+                    y_range_name=self._y_range_name)
 
         # Set legend defaults if there are multiple series.
         if color_column is not None: