axe_the_quotes.py

def axe_quotes(line):
    if '"' not in line:
        return line

    brackets = 0
    out = ""
    for c in line:
        if c == '<':
            brackets += 1
        elif c == '>':
            brackets -= 1
        elif c == '"' and brackets:
            c = '%22'

        out += c
    return out

with open("ttest.txt") as infile:
    with open("tout.txt", "w") as outfile:
        for line in infile:
            outfile.write(axe_quotes(line))