将字体从URL加载到枕头 记忆速度

问题描述

有没有一种方法可以直接从url（最好是Google Colab）加载带有Pillow库的字体？我尝试过类似

from PIL import Image,ImageDraw,ImageFont ImageFont.truetype("https://github.com/googlefonts/roboto/blob/master/src/hinted/Roboto-Regular.ttf?raw=true",15)

但是我收到了 OSError：无法打开资源的错误。我也尝试过Google字体，但无济于事。

解决方法

您可以
（1）使用urllib.request.urlopen()
通过HTTP GET请求获取字体。 （2）使用@functools.lrucache或@memoization.cache记住结果，这样就不会在每次运行函数和
时都提取字体 （3）使用io.BytesIO

将内容作为文件对象传递

from PIL import ImageFont
import urllib.request
import functools
import io


@functools.lru_cache
def get_font_from_url(font_url):
    return urllib.request.urlopen(font_url).read()


def webfont(font_url):
    return io.BytesIO(get_font_from_url(font_url))


if __name__ == "__main__":
    font_url = "https://github.com/googlefonts/roboto/blob/master/src/hinted/Roboto-Regular.ttf?raw=true"
    with webfont(font_url) as f:
        imgfnt = ImageFont.truetype(f,15)

还有python-memoization（pip install memoization）用于替代记忆方式。用法是

from memoization import cache 

@cache
def get_font_from_url(font_url):
    return urllib.request.urlopen(font_url).read()

记忆速度

没有备注：

In [1]: timeit get_font_from_url(font_url)
The slowest run took 4.95 times longer than the fastest. This could mean that an intermediate result is being cached.
1.32 s ± 1.11 s per loop (mean ± std. dev. of 7 runs,1 loop each)

带有备注：

In [1]: timeit get_font_from_url(font_url)
The slowest run took 11.00 times longer than the fastest. This could mean that an intermediate result is being cached.
271 ns ± 341 ns per loop (mean ± std. dev. of 7 runs,1 loop each)
```t

,

尝试这样：

import requests
from io import BytesIO

req = requests.get("https://github.com/googlefonts/roboto/blob/master/src/hinted/Roboto-Regular.ttf?raw=true")

font = ImageFont.truetype(BytesIO(req.content),72)