From d7bb09a71b119ff8279a9c8ab2e2a56674eb763c Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?=E9=99=88=E9=94=AE=E5=86=AC?= <chenjiandongx@qq.com>
Date: Mon, 13 May 2019 13:43:50 +0800
Subject: [PATCH] Add: mypy checker (#1106)

---
 .gitignore                                     |  3 +++
 pyecharts/charts/base.py                       |  2 +-
 pyecharts/charts/basic_charts/bar.py           |  2 +-
 pyecharts/charts/basic_charts/bmap.py          |  2 +-
 pyecharts/charts/basic_charts/boxplot.py       |  2 +-
 pyecharts/charts/basic_charts/calendar.py      |  2 +-
 pyecharts/charts/basic_charts/effectscatter.py |  2 +-
 pyecharts/charts/basic_charts/funnel.py        |  2 +-
 pyecharts/charts/basic_charts/gauge.py         |  2 +-
 pyecharts/charts/basic_charts/geo.py           |  6 +++---
 pyecharts/charts/basic_charts/graph.py         |  2 +-
 pyecharts/charts/basic_charts/heatmap.py       |  2 +-
 pyecharts/charts/basic_charts/line.py          |  2 +-
 pyecharts/charts/basic_charts/liquid.py        |  2 +-
 pyecharts/charts/basic_charts/map.py           |  2 +-
 pyecharts/charts/basic_charts/parallel.py      |  2 +-
 pyecharts/charts/basic_charts/pie.py           |  2 +-
 pyecharts/charts/basic_charts/polar.py         |  2 +-
 pyecharts/charts/basic_charts/radar.py         | 11 +----------
 pyecharts/charts/basic_charts/sankey.py        |  2 +-
 pyecharts/charts/basic_charts/scatter.py       |  2 +-
 pyecharts/charts/basic_charts/sunburst.py      |  2 +-
 pyecharts/charts/basic_charts/themeriver.py    |  2 +-
 pyecharts/charts/basic_charts/tree.py          |  2 +-
 pyecharts/charts/basic_charts/treemap.py       |  2 +-
 pyecharts/charts/basic_charts/wordcloud.py     |  2 +-
 pyecharts/charts/chart.py                      |  6 +++---
 pyecharts/charts/composite_charts/grid.py      |  2 +-
 pyecharts/charts/composite_charts/timeline.py  |  6 +++---
 pyecharts/components/table.py                  |  2 +-
 pyecharts/render/snapshot.py                   |  2 +-
 31 files changed, 39 insertions(+), 45 deletions(-)

diff --git a/.gitignore b/.gitignore
index bd27b2c3..0ef128ad 100644
--- a/.gitignore
+++ b/.gitignore
@@ -99,3 +99,6 @@ ENV/
 # example
 example/*.png
 example/*.html
+
+# mypy
+.mypy_cache/
diff --git a/pyecharts/charts/base.py b/pyecharts/charts/base.py
index e87212a8..eca9e6e8 100644
--- a/pyecharts/charts/base.py
+++ b/pyecharts/charts/base.py
@@ -21,7 +21,7 @@ class Base:
     `Base`类是所有图形类的基类，提供部分初始化参数和基本的方法
     """
 
-    def __init__(self, init_opts: Union[InitOpts, dict] = InitOpts()):
+    def __init__(self, init_opts: InitOpts = InitOpts()):
         self.width = init_opts.width
         self.height = init_opts.height
         self.renderer = init_opts.renderer
diff --git a/pyecharts/charts/basic_charts/bar.py b/pyecharts/charts/basic_charts/bar.py
index a5743d83..8b7c8f45 100644
--- a/pyecharts/charts/basic_charts/bar.py
+++ b/pyecharts/charts/basic_charts/bar.py
@@ -12,7 +12,7 @@ class Bar(RectChart):
     with heights or lengths proportional to the values that they represent.
     """
 
-    def __init__(self, init_opts: Union[opts.InitOpts, dict] = opts.InitOpts()):
+    def __init__(self, init_opts: opts.InitOpts = opts.InitOpts()):
         super().__init__(init_opts=init_opts)
         self.options.update(yAxis=[opts.AxisOpts().opts])
 
diff --git a/pyecharts/charts/basic_charts/bmap.py b/pyecharts/charts/basic_charts/bmap.py
index 185b6cc9..5d8e6100 100644
--- a/pyecharts/charts/basic_charts/bmap.py
+++ b/pyecharts/charts/basic_charts/bmap.py
@@ -14,7 +14,7 @@ class BMap(GeoChartBase):
     Support scatter plot, line
     """
 
-    def __init__(self, init_opts: Union[opts.InitOpts, dict] = opts.InitOpts()):
+    def __init__(self, init_opts: opts.InitOpts = opts.InitOpts()):
         super().__init__(init_opts=init_opts)
         self.js_dependencies.add("bmap")
         self._is_geo_chart = True
diff --git a/pyecharts/charts/basic_charts/boxplot.py b/pyecharts/charts/basic_charts/boxplot.py
index 5d7e85ec..4ad57d23 100644
--- a/pyecharts/charts/basic_charts/boxplot.py
+++ b/pyecharts/charts/basic_charts/boxplot.py
@@ -13,7 +13,7 @@ class Boxplot(RectChart):
     of a set of data.
     """
 
-    def __init__(self, init_opts: Union[opts.InitOpts, dict] = opts.InitOpts()):
+    def __init__(self, init_opts: opts.InitOpts = opts.InitOpts()):
         super().__init__(init_opts=init_opts)
         self.options.update(yAxis=[opts.AxisOpts().opts])
 
diff --git a/pyecharts/charts/basic_charts/calendar.py b/pyecharts/charts/basic_charts/calendar.py
index 486baf36..978fb72b 100644
--- a/pyecharts/charts/basic_charts/calendar.py
+++ b/pyecharts/charts/basic_charts/calendar.py
@@ -12,7 +12,7 @@ class Calendar(Chart):
     Two categories of axes must be used in rectangular coordinates.
     """
 
-    def __init__(self, init_opts: Union[opts.InitOpts, dict] = opts.InitOpts()):
+    def __init__(self, init_opts: opts.InitOpts = opts.InitOpts()):
         super().__init__(init_opts=init_opts)
         self.options.update(calendar=opts.CalendarOpts().opts)
 
diff --git a/pyecharts/charts/basic_charts/effectscatter.py b/pyecharts/charts/basic_charts/effectscatter.py
index f2c4e02d..09217277 100644
--- a/pyecharts/charts/basic_charts/effectscatter.py
+++ b/pyecharts/charts/basic_charts/effectscatter.py
@@ -11,7 +11,7 @@ class EffectScatter(RectChart):
     Use animation effects to visually highlight designated data set.
     """
 
-    def __init__(self, init_opts: Union[opts.InitOpts, dict] = opts.InitOpts()):
+    def __init__(self, init_opts: opts.InitOpts = opts.InitOpts()):
         super().__init__(init_opts=init_opts)
         self.options.update(yAxis=[opts.AxisOpts().opts])
 
diff --git a/pyecharts/charts/basic_charts/funnel.py b/pyecharts/charts/basic_charts/funnel.py
index f3b16652..e1b95542 100644
--- a/pyecharts/charts/basic_charts/funnel.py
+++ b/pyecharts/charts/basic_charts/funnel.py
@@ -15,7 +15,7 @@ class Funnel(Chart):
     and then decisions can be made.
     """
 
-    def __init__(self, init_opts: Union[opts.InitOpts, dict] = opts.InitOpts()):
+    def __init__(self, init_opts: opts.InitOpts = opts.InitOpts()):
         super().__init__(init_opts=init_opts)
 
     def add(
diff --git a/pyecharts/charts/basic_charts/gauge.py b/pyecharts/charts/basic_charts/gauge.py
index 21e1094e..a3ae14ec 100644
--- a/pyecharts/charts/basic_charts/gauge.py
+++ b/pyecharts/charts/basic_charts/gauge.py
@@ -11,7 +11,7 @@ class Gauge(Chart):
     The gauge displays a single key business measure.
     """
 
-    def __init__(self, init_opts: Union[opts.InitOpts, dict] = opts.InitOpts()):
+    def __init__(self, init_opts: opts.InitOpts = opts.InitOpts()):
         super().__init__(init_opts=init_opts)
 
     def add(
diff --git a/pyecharts/charts/basic_charts/geo.py b/pyecharts/charts/basic_charts/geo.py
index 8a7e5163..f03b6921 100644
--- a/pyecharts/charts/basic_charts/geo.py
+++ b/pyecharts/charts/basic_charts/geo.py
@@ -9,7 +9,7 @@ from ...globals import ChartType, TooltipFormatterType
 
 
 class GeoChartBase(Chart):
-    def __init__(self, init_opts: Union[opts.InitOpts, dict] = opts.InitOpts()):
+    def __init__(self, init_opts: opts.InitOpts = opts.InitOpts()):
         super().__init__(init_opts=init_opts)
         self.set_global_opts()
         self._coordinates = COORDINATES
@@ -27,7 +27,7 @@ class GeoChartBase(Chart):
                 self.add_coordinate(k, v[0], v[1])
         return self
 
-    def get_coordinate(self, name: str) -> Sequence:
+    def get_coordinate(self, name: str) -> Optional[Sequence]:
         if name in self._coordinates:
             return self._coordinates[name]
 
@@ -165,7 +165,7 @@ class Geo(GeoChartBase):
     support scatter plot and line
     """
 
-    def __init__(self, init_opts: Union[opts.InitOpts, dict] = opts.InitOpts()):
+    def __init__(self, init_opts: opts.InitOpts = opts.InitOpts()):
         super().__init__(init_opts=init_opts)
         self._coordinate_system: Optional[str] = "geo"
 
diff --git a/pyecharts/charts/basic_charts/graph.py b/pyecharts/charts/basic_charts/graph.py
index c9c923c8..03490030 100644
--- a/pyecharts/charts/basic_charts/graph.py
+++ b/pyecharts/charts/basic_charts/graph.py
@@ -11,7 +11,7 @@ class Graph(Chart):
     The graph is used to represent the relational data.
     """
 
-    def __init__(self, init_opts: Union[opts.InitOpts, dict] = opts.InitOpts()):
+    def __init__(self, init_opts: opts.InitOpts = opts.InitOpts()):
         super().__init__(init_opts=init_opts)
 
     def add(
diff --git a/pyecharts/charts/basic_charts/heatmap.py b/pyecharts/charts/basic_charts/heatmap.py
index 3367b0b4..128cbee9 100644
--- a/pyecharts/charts/basic_charts/heatmap.py
+++ b/pyecharts/charts/basic_charts/heatmap.py
@@ -13,7 +13,7 @@ class HeatMap(RectChart):
     Two categories of axes must be used in rectangular coordinates.
     """
 
-    def __init__(self, init_opts: Union[opts.InitOpts, dict] = opts.InitOpts()):
+    def __init__(self, init_opts: opts.InitOpts = opts.InitOpts()):
         super().__init__(init_opts=init_opts)
         self.options.update(yAxis=[opts.AxisOpts().opts])
         self.set_global_opts(visualmap_opts=opts.VisualMapOpts(orient="horizontal"))
diff --git a/pyecharts/charts/basic_charts/line.py b/pyecharts/charts/basic_charts/line.py
index 6c4f180a..9f2df706 100644
--- a/pyecharts/charts/basic_charts/line.py
+++ b/pyecharts/charts/basic_charts/line.py
@@ -12,7 +12,7 @@ class Line(RectChart):
     with single line to show the change trend of data.
     """
 
-    def __init__(self, init_opts: Union[opts.InitOpts, dict] = opts.InitOpts()):
+    def __init__(self, init_opts: opts.InitOpts = opts.InitOpts()):
         super().__init__(init_opts=init_opts)
         self.options.update(yAxis=[opts.AxisOpts().opts])
 
diff --git a/pyecharts/charts/basic_charts/liquid.py b/pyecharts/charts/basic_charts/liquid.py
index e40e43d5..c4818b7f 100644
--- a/pyecharts/charts/basic_charts/liquid.py
+++ b/pyecharts/charts/basic_charts/liquid.py
@@ -11,7 +11,7 @@ class Liquid(Chart):
     The liquid chart is mainly used to highlight the percentage of data.
     """
 
-    def __init__(self, init_opts: Union[opts.InitOpts, dict] = opts.InitOpts()):
+    def __init__(self, init_opts: opts.InitOpts = opts.InitOpts()):
         super().__init__(init_opts=init_opts)
         self.js_dependencies.add("echarts-liquidfill")
 
diff --git a/pyecharts/charts/basic_charts/map.py b/pyecharts/charts/basic_charts/map.py
index 7b9f6e59..f750c14e 100644
--- a/pyecharts/charts/basic_charts/map.py
+++ b/pyecharts/charts/basic_charts/map.py
@@ -11,7 +11,7 @@ class Map(Chart):
     Map are mainly used for visualization of geographic area data.
     """
 
-    def __init__(self, init_opts: Union[opts.InitOpts, dict] = opts.InitOpts()):
+    def __init__(self, init_opts: opts.InitOpts = opts.InitOpts()):
         super().__init__(init_opts=init_opts)
 
     def add(
diff --git a/pyecharts/charts/basic_charts/parallel.py b/pyecharts/charts/basic_charts/parallel.py
index a0c19515..47795dda 100644
--- a/pyecharts/charts/basic_charts/parallel.py
+++ b/pyecharts/charts/basic_charts/parallel.py
@@ -12,7 +12,7 @@ class Parallel(Chart):
     high dimensional data.
     """
 
-    def __init__(self, init_opts: Union[opts.InitOpts, dict] = opts.InitOpts()):
+    def __init__(self, init_opts: opts.InitOpts = opts.InitOpts()):
         super().__init__(init_opts=init_opts)
         self.options.update(parallel=opts.ParallelOpts().opts)
 
diff --git a/pyecharts/charts/basic_charts/pie.py b/pyecharts/charts/basic_charts/pie.py
index 61332a1a..1844d9ee 100644
--- a/pyecharts/charts/basic_charts/pie.py
+++ b/pyecharts/charts/basic_charts/pie.py
@@ -13,7 +13,7 @@ class Pie(Chart):
     the number of data points.
     """
 
-    def __init__(self, init_opts: Union[opts.InitOpts, dict] = opts.InitOpts()):
+    def __init__(self, init_opts: opts.InitOpts = opts.InitOpts()):
         super().__init__(init_opts=init_opts)
 
     def add(
diff --git a/pyecharts/charts/basic_charts/polar.py b/pyecharts/charts/basic_charts/polar.py
index 2ba9aa86..670be013 100644
--- a/pyecharts/charts/basic_charts/polar.py
+++ b/pyecharts/charts/basic_charts/polar.py
@@ -11,7 +11,7 @@ class Polar(Chart):
     Polar coordinates can be used for scatter and polyline graphs.
     """
 
-    def __init__(self, init_opts: Union[opts.InitOpts, dict] = opts.InitOpts()):
+    def __init__(self, init_opts: opts.InitOpts = opts.InitOpts()):
         super().__init__(init_opts=init_opts)
         self.add_schema()
 
diff --git a/pyecharts/charts/basic_charts/radar.py b/pyecharts/charts/basic_charts/radar.py
index 5eb7b7ef..ee021a4e 100644
--- a/pyecharts/charts/basic_charts/radar.py
+++ b/pyecharts/charts/basic_charts/radar.py
@@ -11,7 +11,7 @@ class Radar(Chart):
     Radar maps are mainly used to represent multivariable data.
     """
 
-    def __init__(self, init_opts: Union[opts.InitOpts, dict] = opts.InitOpts()):
+    def __init__(self, init_opts: opts.InitOpts = opts.InitOpts()):
         super().__init__(init_opts=init_opts)
 
     def add_schema(
@@ -56,15 +56,6 @@ class Radar(Chart):
         areastyle_opts: opts.AreaStyleOpts = opts.AreaStyleOpts(),
         tooltip_opts: Union[opts.TooltipOpts, dict, None] = None,
     ):
-        if isinstance(label_opts, opts.LabelOpts):
-            label_opts = label_opts.opts
-        if isinstance(linestyle_opts, opts.LineStyleOpts):
-            linestyle_opts = linestyle_opts.opts
-        if isinstance(areastyle_opts, opts.AreaStyleOpts):
-            areastyle_opts = areastyle_opts.opts
-        if isinstance(tooltip_opts, opts.TooltipOpts):
-            tooltip_opts = tooltip_opts.opts
-
         self._append_legend(series_name, is_selected)
         self.options.get("series").append(
             {
diff --git a/pyecharts/charts/basic_charts/sankey.py b/pyecharts/charts/basic_charts/sankey.py
index 59d98071..3344814b 100644
--- a/pyecharts/charts/basic_charts/sankey.py
+++ b/pyecharts/charts/basic_charts/sankey.py
@@ -13,7 +13,7 @@ class Sankey(Chart):
     the intermediate process of processing, transformation to the final form.
     """
 
-    def __init__(self, init_opts: Union[opts.InitOpts, dict] = opts.InitOpts()):
+    def __init__(self, init_opts: opts.InitOpts = opts.InitOpts()):
         super().__init__(init_opts=init_opts)
 
     def add(
diff --git a/pyecharts/charts/basic_charts/scatter.py b/pyecharts/charts/basic_charts/scatter.py
index e09d4772..3eb90aa1 100644
--- a/pyecharts/charts/basic_charts/scatter.py
+++ b/pyecharts/charts/basic_charts/scatter.py
@@ -14,7 +14,7 @@ class Scatter(RectChart):
     visualmap component can be used.
     """
 
-    def __init__(self, init_opts: Union[opts.InitOpts, dict] = opts.InitOpts()):
+    def __init__(self, init_opts: opts.InitOpts = opts.InitOpts()):
         super().__init__(init_opts=init_opts)
         self.options.update(yAxis=[opts.AxisOpts().opts])
 
diff --git a/pyecharts/charts/basic_charts/sunburst.py b/pyecharts/charts/basic_charts/sunburst.py
index a18162db..45b54369 100644
--- a/pyecharts/charts/basic_charts/sunburst.py
+++ b/pyecharts/charts/basic_charts/sunburst.py
@@ -14,7 +14,7 @@ class Sunburst(Chart):
     hierarchical relationships like rectangle tree graphs.
     """
 
-    def __init__(self, init_opts: Union[opts.InitOpts, dict] = opts.InitOpts()):
+    def __init__(self, init_opts: opts.InitOpts = opts.InitOpts()):
         super().__init__(init_opts=init_opts)
 
     def add(
diff --git a/pyecharts/charts/basic_charts/themeriver.py b/pyecharts/charts/basic_charts/themeriver.py
index 799b66ba..066a252d 100644
--- a/pyecharts/charts/basic_charts/themeriver.py
+++ b/pyecharts/charts/basic_charts/themeriver.py
@@ -13,7 +13,7 @@ class ThemeRiver(Chart):
     over a period of time.
     """
 
-    def __init__(self, init_opts: Union[opts.InitOpts, dict] = opts.InitOpts()):
+    def __init__(self, init_opts: opts.InitOpts = opts.InitOpts()):
         super().__init__(init_opts=init_opts)
 
     def add(
diff --git a/pyecharts/charts/basic_charts/tree.py b/pyecharts/charts/basic_charts/tree.py
index 22354593..f65717f8 100644
--- a/pyecharts/charts/basic_charts/tree.py
+++ b/pyecharts/charts/basic_charts/tree.py
@@ -13,7 +13,7 @@ class Tree(Chart):
     and right subtrees.
     """
 
-    def __init__(self, init_opts: Union[opts.InitOpts, dict] = opts.InitOpts()):
+    def __init__(self, init_opts: opts.InitOpts = opts.InitOpts()):
         super().__init__(init_opts=init_opts)
 
     @staticmethod
diff --git a/pyecharts/charts/basic_charts/treemap.py b/pyecharts/charts/basic_charts/treemap.py
index 5e14d746..cc25bcb8 100644
--- a/pyecharts/charts/basic_charts/treemap.py
+++ b/pyecharts/charts/basic_charts/treemap.py
@@ -12,7 +12,7 @@ class TreeMap(Chart):
     It mainly uses area to highlight the important nodes in the hierarchy of "tree".
     """
 
-    def __init__(self, init_opts: Union[opts.InitOpts, dict] = opts.InitOpts()):
+    def __init__(self, init_opts: opts.InitOpts = opts.InitOpts()):
         super().__init__(init_opts=init_opts)
 
     def add(
diff --git a/pyecharts/charts/basic_charts/wordcloud.py b/pyecharts/charts/basic_charts/wordcloud.py
index f423a718..400656f9 100644
--- a/pyecharts/charts/basic_charts/wordcloud.py
+++ b/pyecharts/charts/basic_charts/wordcloud.py
@@ -27,7 +27,7 @@ class WordCloud(Chart):
     appear frequently in the text.
     """
 
-    def __init__(self, init_opts: Union[opts.InitOpts, dict] = opts.InitOpts()):
+    def __init__(self, init_opts: opts.InitOpts = opts.InitOpts()):
         super().__init__(init_opts=init_opts)
         self.js_dependencies.add("echarts-wordcloud")
 
diff --git a/pyecharts/charts/chart.py b/pyecharts/charts/chart.py
index b86f5bb1..ab7e736b 100644
--- a/pyecharts/charts/chart.py
+++ b/pyecharts/charts/chart.py
@@ -9,7 +9,7 @@ class Chart(Base):
     `Chart`类是所有非自定义类的基类，继承自 `Base` 类
     """
 
-    def __init__(self, init_opts: Union[opts.InitOpts, dict] = opts.InitOpts()):
+    def __init__(self, init_opts: opts.InitOpts = opts.InitOpts()):
         super().__init__(init_opts=init_opts)
         self.colors = (
             "#c23531 #2f4554 #61a0a8 #d48265 #749f83 #ca8622 #bda29a #6e7074 "
@@ -198,12 +198,12 @@ class Chart3D(Chart):
     `Chart3D`类是所有 3D 类图表的基类，继承自 `Chart` 类
     """
 
-    def __init__(self, init_opts: Union[opts.InitOpts, dict] = opts.InitOpts()):
+    def __init__(self, init_opts: opts.InitOpts = opts.InitOpts()):
         init_opts.renderer = RenderType.CANVAS
         super().__init__(init_opts)
         self.js_dependencies.add("echarts-gl")
         self.options.update(visualMap=opts.VisualMapOpts().opts)
-        self._3d_chart_type = None  # 3d chart type, don't use it directly
+        self._3d_chart_type: Optional[str] = None  # 3d chart type,don't use it directly
 
     def add(
         self,
diff --git a/pyecharts/charts/composite_charts/grid.py b/pyecharts/charts/composite_charts/grid.py
index ee77c9d2..6d3119a7 100644
--- a/pyecharts/charts/composite_charts/grid.py
+++ b/pyecharts/charts/composite_charts/grid.py
@@ -13,7 +13,7 @@ class Grid(Base):
     and scatter chart (bubble chart) can be drawn in grid.
     """
 
-    def __init__(self, init_opts: Union[opts.InitOpts, dict] = opts.InitOpts()):
+    def __init__(self, init_opts: opts.InitOpts = opts.InitOpts()):
         super().__init__(init_opts=init_opts)
         self.options: Optional[dict] = None
         self._axis_index: int = 0
diff --git a/pyecharts/charts/composite_charts/timeline.py b/pyecharts/charts/composite_charts/timeline.py
index 51b78e7f..3f842269 100644
--- a/pyecharts/charts/composite_charts/timeline.py
+++ b/pyecharts/charts/composite_charts/timeline.py
@@ -1,6 +1,6 @@
 from ... import options as opts
 from ...charts.chart import Base
-from ...commons.types import Numeric, Optional, Union
+from ...commons.types import Numeric, Optional, Union, Sequence
 
 
 class Timeline(Base):
@@ -8,11 +8,11 @@ class Timeline(Base):
     `Timeline` provides functions like switching and playing between multiple charts.
     """
 
-    def __init__(self, init_opts: Union[opts.InitOpts, dict] = opts.InitOpts()):
+    def __init__(self, init_opts: opts.InitOpts = opts.InitOpts()):
         super().__init__(init_opts=init_opts)
         self.options = {"baseOption": {"series": [], "timeline": {}}, "options": []}
         self.add_schema()
-        self._time_points = []
+        self._time_points: Sequence = []
 
     def add_schema(
         self,
diff --git a/pyecharts/components/table.py b/pyecharts/components/table.py
index 26e3c420..781293a4 100644
--- a/pyecharts/components/table.py
+++ b/pyecharts/components/table.py
@@ -19,7 +19,7 @@ class Table:
         self.page_title = page_title
         self.js_host = js_host
         self.js_dependencies: OrderedSet = OrderedSet("bulma")
-        self._charts = []
+        self._charts: Sequence = []
 
     def add(self, headers: Sequence, rows: Sequence, attributes: Optional[dict] = None):
 
diff --git a/pyecharts/render/snapshot.py b/pyecharts/render/snapshot.py
index 3ef50695..dab466c4 100644
--- a/pyecharts/render/snapshot.py
+++ b/pyecharts/render/snapshot.py
@@ -88,4 +88,4 @@ def save_as(image_data: bytes, output_name: str, file_type: str):
         b.paste(m, mask=m.split()[3])
         b.save(output_name, file_type, quality=100)
     except ModuleNotFoundError:
-        raise Exception("Please install PIL for % image type" % file_type)
+        raise Exception("Please install PIL for {} image type".format(file_type))