Python 2.7混合迭代和读取方法会丢失数据

Question

我有一些问题可以在Python 3中运行,但在2.7中失败.我有以下部分代码:

---

def getDimensions(file,log):
noStations = 0 
noSpanPts = 0 
dataSet = False

if log:
    print("attempting to retrieve dimensions. Opening file",file)

while not dataSet:      
    try: # read until error occurs
        string = file.readline().rstrip() # to avoid breaking on an empty line
    except IOError:
        break

站

    if "Ax dist hub" in string: # parse out number of stations
        if log:
            print("found ax dist hub location") 
        next(file) # skip empty line
        eos = False # end of stations
        while not eos:
            string = file.readline().rstrip()
            if string =="":
                eos = True
            else:
                noStations = int(string.split()[0])

---

这会返回一个错误:

    ValueError: Mixing iteration and read methods would lose data. 

我知道问题是我如何在while循环中读取我的字符串,或者至少这是我所相信的.有没有快速解决方法？任何帮助表示赞赏.谢谢!

Answer 1

问题是您正在使用next和使用readline相同的文件.正如文档所说:

.由于使用预读缓冲区,将next()与其他文件方法(如readline())结合使用是行不通的.

修复是微不足道的:替换next为readline.