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<p>我叫大卫,我在佛罗里达的一家救护车公司工作。</p>
<p>我正在使用Python 2.7和matplotlib。我正试图进入我的救护车呼叫数据库,并统计每个工作日发生的呼叫次数。</p>
<p>然后,我将使用matplotlib创建此信息的条形图,以向医护人员显示他们每天的忙碌程度。</p>
<p>下面是非常有效的代码:</p>
<pre><code>import pyodbc
import matplotlib.pyplot as plt
MySQLQuery = """
SELECT
DATEPART(WEEKDAY, IIU_tDispatch)AS [DayOfWeekOfCall]
, COUNT(DATEPART(WeekDay, IIU_tDispatch)) AS [DispatchesOnThisWeekday]
FROM AmbulanceIncidents
GROUP BY DATEPART(WEEKDAY, IIU_tDispatch)
ORDER BY DATEPART(WEEKDAY, IIU_tDispatch)
"""
cnxn = pyodbc.connect('DRIVER={SQL Server};SERVER=MyServer;DATABASE=MyDatabase;UID=MyUserID;PWD=MyPassword')
cursor = cnxn.cursor()
GraphCursor = cnxn.cursor()
cursor.execute(MySQLQuery)
#generate a graph to display the data
data = GraphCursor.fetchall()
DayOfWeekOfCall, DispatchesOnThisWeekday = zip(*data)
plt.bar(DayOfWeekOfCall, DispatchesOnThisWeekday)
plt.grid()
plt.title('Dispatches by Day of Week')
plt.xlabel('Day of Week')
plt.ylabel('Number of Dispatches')
plt.show()
</code></pre>
<p>上面显示的代码工作得很好。它返回一个漂亮的图表,我很高兴。我只想做一个改变。</p>
<p>它显示的是整数,而不是显示一周中日期的名称的X轴,例如“Sunday”。换句话说,星期天是1,星期一是2,等等</p>
我的修正是,我改写我的SQL查询使用DeNeNeMe()代替DATEPARTE()。
下面显示的是我的sql代码,用于返回周的名称(而不是整数)。</p>
<pre><code>SELECT
DATENAME(WEEKDAY, IIU_tDispatch)AS [DayOfWeekOfCall]
, COUNT(DATENAME(WeekDay, IIU_tDispatch)) AS [DispatchesOnThisWeekday]
FROM AmbulanceIncidents
GROUP BY DATENAME(WEEKDAY, IIU_tDispatch)
ORDER BY DATENAME(WEEKDAY, IIU_tDispatch)
</code></pre>
<p>我的python代码中的其他内容保持不变。但是这不起作用,我无法理解错误消息。</p>
<p>以下是错误消息:</p>
<pre><code>Traceback (most recent call last):
File "C:\Documents and Settings\kulpandm\workspace\FiscalYearEndReport\CallVolumeByDayOfWeek.py", line 59, in
<module>
plt.bar(DayOfWeekOfCall, DispatchesOnThisWeekday)
File "C:\Python27\lib\site-packages\matplotlib\pyplot.py", line 2080, in bar
ret = ax.bar(left, height, width, bottom, **kwargs)
File "C:\Python27\lib\site-packages\matplotlib\axes.py", line 4740, in bar
self.add_patch(r)
File "C:\Python27\lib\site-packages\matplotlib\axes.py", line 1471, in add_patch
self._update_patch_limits(p)
File "C:\Python27\lib\site-packages\matplotlib\axes.py", line 1489, in _update_patch_limits
xys = patch.get_patch_transform().transform(vertices)
File "C:\Python27\lib\site-packages\matplotlib\patches.py", line 547, in get_patch_transform
self._update_patch_transform()
File "C:\Python27\lib\site-packages\matplotlib\patches.py", line 543, in _update_patch_transform
bbox = transforms.Bbox.from_bounds(x, y, width, height)
File "C:\Python27\lib\site-packages\matplotlib\transforms.py", line 745, in from_bounds
return Bbox.from_extents(x0, y0, x0 + width, y0 + height)
TypeError: coercing to Unicode: need string or buffer, float found
</code></pre>
<p>我想不通。</p>
<p>综上所述,当我用x轴作为整数输出数据时,y轴显示救护车事故的数量,Matplotlib将生成一个很好的图表。但当我的数据输出是x轴时,它是一个字符串(星期日、星期一等)。那么Matplotlib将不工作。</p>
<p>我在Google上做了几个小时的研究,阅读了matplotlib文档。
请帮帮我。我希望使用Matplotlib作为我的报告引擎。</p>