使用 Flask 显示 matplotlib 图

Question

我想在我的 Flask Web 项目中可视化绘图 (SciView)。

这是我的代码：

import matplotlib.pyplot as plt 
# x-coordinates of left sides of bars 
left = [1, 2, 3, 4, 5] 
# heights of bars 
height = [10, 24, 36, 40, 5] 
# labels for bars 
tick_label = ['one', 'two', 'three', 'four', 'five'] 
# plotting a bar chart 
plt.bar(left, height, tick_label=tick_label, width=0.8, color=['red', 'green']) 
# naming the y-axis 
plt.xlabel('y - axis') 
# naming the x-axis 
plt.xlabel('x - axis') 
# plot title 
plt.title('My bar chart!') 
# function to show the plot 
plt.show()

我尝试在 Flask 项目中运行此代码，但没有输出。

Answer 1

一个可能的解决方案是保存图形plt.savefig并将其附加到 HTML<img>标记。

from flask import Flask, render_template
import matplotlib.pyplot as plt

app = Flask(__name__)

@app.route('/plot')
def plot():
    left = [1, 2, 3, 4, 5]
    # heights of bars
    height = [10, 24, 36, 40, 5]
    # labels for bars
    tick_label = ['one', 'two', 'three', 'four', 'five']
    # plotting a bar chart
    plt.bar(left, height, tick_label=tick_label, width=0.8, color=['red', 'green'])

    # naming the y-axis
    plt.ylabel('y - axis')
    # naming the x-axis
    plt.xlabel('x - axis')
    # plot title
    plt.title('My bar chart!')

    plt.savefig('static/images/plot.png')

    return render_template('plot.html', url='/static/images/plot.png')

if __name__ == '__main__':
   app.run()

然后在模板/plot.html

<img src={{url}} alt="Chart" height="auto" width="100%">