如何顯示數據標籤時，您將鼠標放在數據

Question

我繪製的一些數據，看起來像

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 

我的基本步驟是

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() 

但是我真的很想讓每名學校時，我將鼠標懸停在圖表上，以便我可以瀏覽數據。有沒有辦法做到這一點？

Answer 1

只需插上我自己的項目，看看mpldatacursor：https://github.com/joferkington/mpldatacursor

作爲一個基本的例子，只是打電話datacursor(hover=True, point_labels=df['E'])將讓你90％的方式，你想要什麼。例如，把你的代碼上面的代碼片段：

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() 

我們會得到每當線懸停在彈出的標籤。

但是，通過設計，默認行爲是在線路懸停/點擊時顯示彈出窗口。因此，使用point_labels選項時，結果可能不完全是你腦子裏想的是什麼：

如果你只希望在頂點盤旋在要顯示的彈出窗口中，你可以使用類似這樣的一種解決方法：（將有隻顯示彈出在下一版本的頂點選擇，所以這種解決方法不會在將來需要）

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() 

此外，您可能只想顯示有問題的學校，而不是x，y座標等。要更改此設置，請使用自定義formatter功能：

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

最後，你可能想要一個白色的盒子票友箭頭和不同的相對位置：

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)) 

只是把它在最後一個例子中全部集成到可運行版本中：

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()