只有当它以特定单词开头时才打印下一行(print next line only if it begins with a specific word)

 我对python有点新意，我想知道是否有人可以提供帮助。 基本上我正在读取文件的内容，当我找到单词“prb”时，我想使用next（）函数检查下一行，如果它以单词“rt”开头，我想打印两行。 到目前为止，我写了这段代码： 
 
    with open('/home/user/Desktop/3rdstep.txt', 'r') as f:
    f.readline()
    for line in f:
            if "prb" in line:
                    try:
                            myword = next(f)
                            if "rt" in myword:
                                    print(line.strip())
                                    print(myword)
                    except:
                            print("pass")
 
 这很好但唯一的问题是它会随机跳过“rt”字，原因我不知道。 任何人都可以帮忙或让别人做类似的事吗？ 
 
 谢谢 

I am a bit new to python and I was wondering if anyone can help. Basically I am reading contents of a file and when I find the word "prb" I want to check the next line using the next() function and if it starts with the word "rt", i want to print both lines. So far I wrote this piece of code:
 
    with open('/home/user/Desktop/3rdstep.txt', 'r') as f:
    f.readline()
    for line in f:
            if "prb" in line:
                    try:
                            myword = next(f)
                            if "rt" in myword:
                                    print(line.strip())
                                    print(myword)
                    except:
                            print("pass")
 
This works fine but the only problem is that it skips randomly "rt" words for a reason I don't know. Can anyone help please or have someone done something similar?
 
Thanks

原文：https://stackoverflow.com/questions/37032554