Markdownの$$で囲まれたTex数式を画像に置き換えてGitHubなどで表示できるようにするスクリプト

md-tex2img.py

#!/usr/bin/env python3
import sys

pattern = '<img src="https://latex.codecogs.com/png.latex?{}" />'

with open(sys.argv[1] ,"r") as f:
    new_lines = ""
    while True:
        new_line = ""
        line = f.readline()
        while line.find("$$\n") >= 0:
            line = f.readline()
            math = line.replace(" ","&space;")[:-1]
            tag = pattern.format(math)
            new_line = "\n" + tag + "\n\n"
            new_lines += new_line
            f.readline()
            line = f.readline()
        new_line = ""
        s = line.find("$$")
        if s < 0:
            new_line = line
        e = -2
        while s >= 0:
            new_line += line[e+2:s]
            e = line.find("$$",s+2)
            math = line[s+2:e]
            math = math.replace(" ","&space;")
            if s != 0:
                math = '\inline&space;' + math
            tag = pattern.format(math)
            new_line += tag
            s = line.find("$$",e+2)
            if s < 0:
                new_line += line[e+2::]
        new_lines += new_line
        if not line:
            break

with open(sys.argv[1],"w") as f:
    f.write(new_lines)