输出仅是数据的最后一行。 如何四处移动代码以解决此问题？

Question

I've been moving my file.write expression in, out, and around the loop, but no matter what, I don't get the full list, only the last one.This problem has been addressed with Python: Only writes last line of output but that thread doesn't give a clear solution.

I've tried with "w" and "a" but not successful with either.I also tried with "for line in f".

The other issue is that what I want to output is a tuple, and when I print it, I get exactly what I want it to look like, ie

    14_sec.wav 14
    16_sec.wav 16

but I've been converting it to a str in order to satisfy the write() requirement and so it doesn't appear that way in the output file.

My code is like this:

    path="/Volumes/LaCie/VoicemailDownload/test"
    res_file = "fileLengths.csv"

for filename in os.listdir(path):
    if filename.endswith(".wav"):
        with open (filename, 'r') as f:

            f.seek(28)
            a = f.read(4)
            byteRate=0
            for i in range(4):
                byteRate=byteRate + ord(a[i])*pow(256,i)

                fileSize=os.path.getsize(filename)

                ms=((fileSize-44)*1000)/byteRate
                sec = ms/1000
                res = filename, sec
            print filename, sec

        with open (res_file, "w") as results:
            #for line in f:
            results.write(str(res))

Answer 1

I solved it by importing pandas and then exporting as a csv file, which worked great:

    data = pandas.DataFrame([])
    for filename in os.listdir(path):
        if filename.endswith(".wav"):
            f = open(filename, 'r')
            f.seek(28)
            a = f.read(4)
            byteRate=0

            for i in range(1,4):
                byteRate=byteRate + ord(a[i])*pow(256,i)

                fileSize=os.path.getsize(filename)

                ms=((fileSize-44)*1000)/byteRate
                sec = ms/1000
                counter += 1
            data = data.append(pandas.DataFrame({'Filename':filename, 'Sec': sec},index = [counter]), ignore_index=True)

            newdata = data.to_csv(index=False)

            with open(res_file, 'w') as results:
                results.write(str(newdata))