类别轴与值轴相交的设置值问题

Question

我在设置类别轴与值轴相交的值时遇到问题。下面是代码示例

import time
import datetime


import traceback
import sys
from pptx import Presentation
from pptx.chart.data import ChartData
from pptx.enum.chart import XL_CHART_TYPE,XL_AXIS_CROSSES
from pptx.util import Inches
import pptx
from pptx import Presentation
from pptx.util import Cm, Pt
from pptx.enum.text import MSO_ANCHOR,MSO_VERTICAL_ANCHOR, MSO_AUTO_SIZE,PP_ALIGN
from pptx.chart.data import CategoryChartData, ChartData
from pptx.enum.chart import XL_CHART_TYPE
from pptx.enum.chart import XL_TICK_MARK, XL_MARKER_STYLE
from pptx.enum.chart import XL_LEGEND_POSITION
from pptx.dml.chtfmt import ChartFormat
from pptx.dml.line import LineFormat
from pptx.dml.color import ColorFormat, RGBColor
from pptx.enum.dml import MSO_LINE
prs = Presentation()
slide = prs.slides.add_slide(prs.slide_layouts[5])
chart_data = ChartData()


chart_data.categories = [datetime.datetime.strptime('2012-02-09', '%Y-%m-%d'), datetime.datetime.strptime('2012-04-09', '%Y-%m-%d'), datetime.datetime.strptime('2012-09-09', '%Y-%m-%d')]
chart_data.add_series('West',    (32.2, 28.4, 34.7))
chart_data.add_series('East',    (24.3, 30.6, 20.2))
chart_data.add_series('Midwest', (20.4, 18.3, 26.2))
x, y, cx, cy = Inches(2), Inches(2), Inches(6), Inches(4.5)
chart = slide.shapes.add_chart(
    XL_CHART_TYPE.LINE_MARKERS, x, y, cx, cy, chart_data
).chart
chart.has_legend = True
chart.legend.include_in_layout = False
chart.series[0].smooth = True
points = chart.plots[0].series[0].points
ccount = 1;
period = int(len(points)/1.0)
chart.plots[0].series[0].marker.style = XL_MARKER_STYLE.NONE
for point in points:
    if ccount== period:
        point.marker.style = 8
        fill = point.marker.format.fill
        fill.solid()
        fill.fore_color.rgb = RGBColor(*[0,0,0])
        point.marker.format.line.color.rgb = RGBColor(*[0,0,0])
        ccount = 1
    else:
        ccount +=1

try:
    chart.value_axis.crosses = XL_AXIS_CROSSES.MINIMUM
except Exception as error:
    traceback.print_exc()


chart.has_legend = True
chart.legend.include_in_layout = False
chart.legend.position = XL_LEGEND_POSITION.BOTTOM
chart.legend.font.size = Pt(6)

prs.save('chart-01.pptx')

Python iterpreter 显示这样的错误：

Traceback (most recent call last): File "", line 56, in chart.value_axis.crosses = XL_AXIS_CROSSES.MINIMUM File "C:\Users*\AppData\Local\Continuum\anaconda3\lib\site-packages\pptx\chart\axis.py", line 433, in crosses cross_xAx = self._cross_xAx File "C:\Users*\AppData\Local\Continuum\anaconda3\lib\site-packages\pptx\chart\axis.py", line 512, in _cross_xAx cross_axId = self._element.xpath(expr)[0] IndexError: list index out of range

我认为问题在于类别轴内的日期时间值。因为如果我根据另一种类型的对象（字符串、浮点数或整数）创建这个轴，一切都会好的！

如有任何帮助，我们将不胜感激！

Answer 1

好的，这看起来像是 ValueAxis 代码中的一个空白，我们在前一段时间添加 DateAxis 时遗漏了。

试试这个。将此函数添加到代码中方便的地方：

from ..enum.chart import XL_AXIS_CROSSES


def set_date_crosses(value_axis, value):
    """*value* is a member of XL_AXIS_CROSSES."""
    xAx = value_axis._elemement

    def _cross_xAx(self):
        """Axis element in same group (pri/sec) that crosses this axis."""
        crossAx_id = xAx.crossAx.val
        expr = (
            '(../c:catAx | ../c:valAx | ../c:dateAx)/c:axId[@val="%d"]'
            % crossAx_id
        )
        cross_axId = xAx.xpath(expr)[0]
        return cross_axId.getparent()

    cross_xAx = _cross_xAx()

    if value == XL_AXIS_CROSSES.CUSTOM:
        if cross_xAx.crossesAt is not None:
            return

    cross_xAx._remove_crosses()
    cross_xAx._remove_crossesAt()

    if value == XL_AXIS_CROSSES.CUSTOM:
        cross_xAx._add_crossesAt(val=0.0)
        return

    cross_xAx._add_crosses(val=value)

然后将 chart.value_axis.crosses = XL_AXIS_CROSSES.MINIMUM 更改为：

set_date_crosses(chart.value_axis, XL_AXIS_CROSSES.MINIMUM)

看看是否能解决问题。

如果可行，请告诉我，我会开一个案例将更改合并到下一个版本中。

类别轴与值轴相交的设置值问题

Problem with setting value at which category axis intersect value axis

python

python-pptx