Markdown解析图片路径、上传图床并替换路径

开始

首先假设你hexo new title了一篇文章，并写好了内容：

...
![](~/img/1.png)
![](~/img/2.png)
![](~/img/3.png)
...

如果你的博客托管在GitHub上，博客的图片需要请求很久才能显示出来。这是因为上传到GitHub的图片往往需要请求海外服务器，而访问图床的通讯代价比较大。
为此，我们需要将图片放到一个高速的图床服务器上，将图片与文本分别存储在不同的服务器上。本篇博客我推荐sm.ms图床（免费）。

上传图片到sm.ms

调用sm.ms的API，并将调用结果返回

def post_img(filePath):
    headers = {
        'Authorization': '你的API ID',
    }
    try:
        data = {
            'smfile': (filePath.split('/')[-1], open(filePath, 'rb')),
            'format': 'json'
        }
    except:
        return False
    res = requests.post('https://sm.ms/api/v2/upload', headers=headers, files=data).text
    return json.loads(res)

调用成功后的返回内容：

{
    "success": true,
    "code": "success",
    "message": "Upload success.",
    "data": {
        "file_id": 0,
        "width": 4677,
        "height": 3307,
        "filename": "luo.jpg",
        "storename": "D5VpWCKFElUsPcR.jpg",
        "size": 801933,
        "path": "/2019/12/16/D5VpWCKFElUsPcR.jpg",
        "hash": "Q6vLIbCGZojrMhO2e7BmgFuXRV",
        "url": "https://vip1.loli.net/2019/12/16/D5VpWCKFElUsPcR.jpg",
        "delete": "https://sm.ms/delete/Q6vLIbCGZojrMhO2e7BmgFuXRV",
        "page": "https://sm.ms/image/D5VpWCKFElUsPcR"
    },
    "RequestId": "8A84DDCA-96B3-4363-B5DF-524E95A5201A"
}

解析Markdown

正则表达式：

1	aims = re.findall('!\[.?\]\((.?)\)', markdown_content, re.M) # re.M 跨行匹配

通过这个表达式，我们可以将文件中的所有图片路径解析出来，然后再针对每个路径计算它的绝对路径传递给post_img函数上传图床。

绝对路径获取：

def get_path(rt, rel):
    return os.path.abspath(rt+rel)

_user_path = os.path.expanduser('~') # 用户根目录
rt_path = dir_char.join(os.path.abspath(filePath).split(dir_char)[:-1]) + dir_char # MarkDown所在文件夹
for aim in aims:
    raw_path = aim
    aim = aim.replace('~', _user_path)
    aim = aim if aim.startswith(dir_char) else get_path(rt_path, aim)

此时，aim值为绝对路径

上传、替换与结果显示

def format_markdown(filePath):
    _user_path = os.path.expanduser('~')
    rt_path = dir_char.join(os.path.abspath(filePath).split(dir_char)[:-1]) + dir_char
    tb = PrettyTable()
    tb.field_names = ['File', 'Status', 'url']
    img_set = {}
    with open(filePath, 'r') as fp:
        ct = fp.read()
    aims = re.findall('!\[.*?\]\((.*?)\)', ct, re.M)
    for aim in aims:
        raw_path = aim
        aim = aim.replace('~', _user_path)
        aim = aim if aim.startswith(dir_char) else get_path(rt_path, aim)
        if aim not in img_set:
            res = post_img(aim)
            if not res:
                tb.add_row([aim.split(dir_char)[-1], 'No File', ''])
                img_set[aim] = False
            else:
                tb.add_row([aim.split(dir_char)[-1], res['success'], '' if not res['success'] else res['data']['url']])
                img_set[aim] = res['data']['url']
        if img_set[aim]:
            ct = ct.replace(raw_path, img_set[aim])
    with open(filePath, 'w') as fp:
        fp.write(ct)
    print(tb)

全部代码

import requests
import json
import sys
import re
import os
from prettytable import PrettyTable

if sys.platform.startswith('win'):
    dir_char = '\\'
else:
    dir_char = '/'


def post_img(filePath):
    headers = {
        'Authorization': 'MEQCiM6viKEEF8RYPRIpOL4DA7oGtwvA',
    }
    try:
        data = {
            'smfile': (filePath.split('/')[-1], open(filePath, 'rb')),
            'format': 'json'
        }
    except:
        return False
    res = requests.post('https://sm.ms/api/v2/upload', headers=headers, files=data).text
    return json.loads(res)


def get_path(rt, rel):
    return os.path.abspath(rt+rel)


def format_markdown(filePath):
    _user_path = os.path.expanduser('~')
    rt_path = dir_char.join(os.path.abspath(filePath).split(dir_char)[:-1]) + dir_char
    tb = PrettyTable()
    tb.field_names = ['File', 'Status', 'url']
    img_set = {}
    with open(filePath, 'r') as fp:
        ct = fp.read()
    aims = re.findall('!\[.*?\]\((.*?)\)', ct, re.M)
    for aim in aims:
        raw_path = aim
        aim = aim.replace('~', _user_path)
        aim = aim if aim.startswith(dir_char) else get_path(rt_path, aim)
        if aim not in img_set:
            res = post_img(aim)
            if not res:
                tb.add_row([aim.split(dir_char)[-1], 'No File', ''])
                img_set[aim] = False
            else:
                tb.add_row([aim.split(dir_char)[-1], res['success'], '' if not res['success'] else res['data']['url']])
                img_set[aim] = res['data']['url']
        if img_set[aim]:
            ct = ct.replace(raw_path, img_set[aim])
    with open(filePath, 'w') as fp:
        fp.write(ct)
    print(tb)

if __name__ == '__main__':
    format_markdown(sys.argv[1])