Question

我的问题是我从HIVE获得了大量数据（大约1000万点）。 Bokeh本身无法处理它。我在下面尝试使用Datashader。但是我在保存图像时遇到了问题：

import pyodbc
import pandas as pd
import datashader as ds
import datashader.transfer_functions as tf

conn = pyodbc.connect("xxxxxxxx", autocommit=True)
df = pd.read_sql("select devalue,fevalue,type from tblbigdata limit 10;",con=conn)
conn.close()

cvs = ds.Canvas(plot_width=400, plot_height=400)

agg = cvs.points(df, 'devalue', 'fevalue', ds.mean('fevalue'))
img = tf.shade(agg, cmap=['lightblue', 'darkblue'], how='log')
img.save("out.png")
print("Done")

获取错误： AttributeError: 'Image' object has no attribute 'save'

Answer 1

这是完整的代码。

import pyodbc
import pandas as pd
import datashader as ds
import datashader.transfer_functions as tf
from PIL import Image

conn = pyodbc.connect("xxxxxxxx", autocommit=True)
df = pd.read_sql("select devalue,fevalue,type from tblbigdata limit 10;",con=conn)
conn.close()

cvs = ds.Canvas(plot_width=400, plot_height=400)

agg = cvs.points(df, 'devalue', 'fevalue', ds.mean('fevalue'))
img = tf.shade(agg, cmap=['lightblue', 'darkblue'], how='log')
Image = img.to_pil()
Image.save("C:\MyPython\myimage123.bmp","BMP")
print("Done")

散景与数百万的大数据

1 个答案: