import sys
def edit(p, pairs):
    s=open(p,encoding='utf-8',newline='').read()
    crlf='\r\n' in s
    for old,new in pairs:
        if crlf: old=old.replace('\n','\r\n'); new=new.replace('\n','\r\n')
        assert s.count(old)==1, (p, old[:80], s.count(old))
        s=s.replace(old,new)
    open(p,'w',encoding='utf-8',newline='').write(s)