python - 将鼠标悬停在数据上时如何显示数据标签

我正在绘制一些看起来像的数据

931,Oxfordshire,9314125,123255,Larkmead School,Abingdon,125,124,20,SUPP,8
931,Oxfordshire,9314126,123256,John Mason School,Abingdon,164,164,25,6,16
931,Oxfordshire,9314127,123257,Fitzharrys School,Abingdon,150,149,9,0,11
931,Oxfordshire,9316076,123298,Our Lady's Abingdon,Abingdon,57,57,SUPP,SUPP,16

我的基本步骤是

df = pandas.read_csv("file.csv", names=['A','B','C','D','E','F','G', 'H','I','J', 'K'], header=None)
df.replace('SUPP', 3.0, inplace=True)
df = df.convert_objects(convert_numeric=True)
df['KG'] = df['K']*1.0/df['G']
plt.plot(result['KG'])
plt.show()

但是，当我将鼠标悬停在图表上时，我真的很想得到每个学校的名称，以便我可以浏览数据。有什么办法吗？

最佳答案

只是插入我自己的项目，看看mpldatacursor:https://github.com/joferkington/mpldatacursor

作为一个基本示例，仅调用datacursor(hover=True, point_labels=df['E'])即可为您提供所需方法的90％。例如，将您的代码段放在上面:

from StringIO import StringIO
import pandas as pd
import matplotlib.pyplot as plt
from mpldatacursor import datacursor

f = StringIO(
"""931,Oxfordshire,9314125,123255,Larkmead School,Abingdon,125,124,20,SUPP,8
931,Oxfordshire,9314126,123256,John Mason School,Abingdon,164,164,25,6,16
931,Oxfordshire,9314127,123257,Fitzharrys School,Abingdon,150,149,9,0,11
931,Oxfordshire,9316076,123298,Our Lady's Abingdon,Abingdon,57,57,SUPP,SUPP,16
""")
df = pd.read_csv(f, names=['A','B','C','D','E','F','G', 'H','I','J', 'K'],
                 header=None)
df.replace('SUPP', 3.0, inplace=True)
df = df.convert_objects(convert_numeric=True)
df['KG'] = df['K']*1.0/df['G']
plt.plot(df['KG'], marker='o')

datacursor(hover=True, point_labels=df['E'])

plt.show()

只要将鼠标悬停在该行上，我们就会获得一个弹出标签。

但是，根据设计，默认行为是每当鼠标悬停在该行上/单击该行时，都会显示弹出窗口。因此，当使用point_labels选项时，结果可能与您的想法不尽相同:

如果只希望将鼠标悬停在弹出窗口上时显示弹出窗口，则可以使用与此类似的解决方法:(在下一个版本中，将有一个选项仅在顶点上显示弹出窗口，因此此解决方法将来不再需要。)

from StringIO import StringIO
import pandas as pd
import matplotlib.pyplot as plt
from mpldatacursor import datacursor

f = StringIO(
"""931,Oxfordshire,9314125,123255,Larkmead School,Abingdon,125,124,20,SUPP,8
931,Oxfordshire,9314126,123256,John Mason School,Abingdon,164,164,25,6,16
931,Oxfordshire,9314127,123257,Fitzharrys School,Abingdon,150,149,9,0,11
931,Oxfordshire,9316076,123298,Our Lady's Abingdon,Abingdon,57,57,SUPP,SUPP,16
""")
df = pd.read_csv(f, names=['A','B','C','D','E','F','G', 'H','I','J', 'K'],
                 header=None)
df.replace('SUPP', 3.0, inplace=True)
df = df.convert_objects(convert_numeric=True)
df['KG'] = df['K']*1.0/df['G']
plt.plot(df['KG'], marker='o')

l, = plt.plot(df['KG'], marker='o', linestyle='', visible=False)
datacursor(l, hover=True, point_labels=df['E'])

plt.show()

另外，您可能只想显示所讨论的学校，而不是x，y坐标等。要更改此设置，请使用自定义formatter函数:

datacursor(l, hover=True, point_labels=df['E'],
           formatter=lambda **kwargs: kwargs['point_label'][0])

最后，您可能希望有一个白色的盒子，上面有一个漂亮的箭头，并且相对位置不同:

datacursor(l, hover=True, point_labels=df['E'], bbox=dict(fc='white'),
           formatter=lambda **kwargs: kwargs['point_label'][0], xytext=(0, 25),
           arrowprops=dict(arrowstyle='simple', fc='white', alpha=0.5))

在最后一个示例中，只是将所有内容放到一个可运行的版本中:

from StringIO import StringIO
import pandas as pd
import matplotlib.pyplot as plt
from mpldatacursor import datacursor

f = StringIO(
"""931,Oxfordshire,9314125,123255,Larkmead School,Abingdon,125,124,20,SUPP,8
931,Oxfordshire,9314126,123256,John Mason School,Abingdon,164,164,25,6,16
931,Oxfordshire,9314127,123257,Fitzharrys School,Abingdon,150,149,9,0,11
931,Oxfordshire,9316076,123298,Our Lady's Abingdon,Abingdon,57,57,SUPP,SUPP,16
""")
df = pd.read_csv(f, names=['A','B','C','D','E','F','G', 'H','I','J', 'K'],
                 header=None)
df.replace('SUPP', 3.0, inplace=True)
df = df.convert_objects(convert_numeric=True)
df['KG'] = df['K']*1.0/df['G']
plt.plot(df['KG'], marker='o')

l, = plt.plot(df['KG'], marker='o', linestyle='', visible=False)
datacursor(l, hover=True, point_labels=df['E'], bbox=dict(fc='white'),
           formatter=lambda **kwargs: kwargs['point_label'][0], xytext=(0, 25))

plt.show()