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@wilsaj
Created March 9, 2011 13:09
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Example of rendering a matplotlib image directly to Flask view
from flask import Flask, make_response
app = Flask(__name__)
@app.route("/simple.png")
def simple():
import datetime
import StringIO
import random
from matplotlib.backends.backend_agg import FigureCanvasAgg as FigureCanvas
from matplotlib.figure import Figure
from matplotlib.dates import DateFormatter
fig=Figure()
ax=fig.add_subplot(111)
x=[]
y=[]
now=datetime.datetime.now()
delta=datetime.timedelta(days=1)
for i in range(10):
x.append(now)
now+=delta
y.append(random.randint(0, 1000))
ax.plot_date(x, y, '-')
ax.xaxis.set_major_formatter(DateFormatter('%Y-%m-%d'))
fig.autofmt_xdate()
canvas=FigureCanvas(fig)
png_output = StringIO.StringIO()
canvas.print_png(png_output)
response=make_response(png_output.getvalue())
response.headers['Content-Type'] = 'image/png'
return response
if __name__ == "__main__":
app.run()
@Usul1980
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this doesn't work in pythonanywhere.com anymore. is it maybe outdated? I keep getting a 404 URL not found

@GreenTeaHua
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mark

@vinaymopidevi
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from flask import Flask, make_response
app = Flask(name)

@app.route("/simple.png")
def simple():
import datetime
from io import BytesIO

import random

from matplotlib.backends.backend_agg import FigureCanvasAgg as FigureCanvas
from matplotlib.figure import Figure
from matplotlib.dates import DateFormatter

fig=Figure()
ax=fig.add_subplot(111)
x=[]
y=[]
now=datetime.datetime.now()
delta=datetime.timedelta(days=1)
for i in range(10):
    x.append(now)
    now+=delta
    y.append(random.randint(0, 1000))
ax.plot_date(x, y, '-')
ax.xaxis.set_major_formatter(DateFormatter('%Y-%m-%d'))
fig.autofmt_xdate()
canvas=FigureCanvas(fig)
png_output =   BytesIO()
canvas.print_png(png_output)
response=make_response(png_output.getvalue())
response.headers['Content-Type'] = 'image/png'
return response

if name == "main":
app.run(debug=True)

@vinaymopidevi
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it is working

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