Question

我想将多个 CSV 文件（对于每个 CSV 文件，我只需要第一列的前五个元素）转换为文本文件。这是我的代码。

将熊猫导入为 pd 导入操作系统

for root, dirs, files in os.walk("./data_v6/level3/"):
    count = 1
    for dir in dirs:
        print(dir)
        count= count+1
        print(count)
        df = pd.read_csv('data_v6/level3/'+dir+'/tweets_topic.csv',usecols=[0])
        print(df.loc[0:4])
        #print(df)
        df.to_csv('data_v6/level3/topic_DIC.txt', header=None, index=None, sep=' ', mode='a')

但是它不能工作。我收到了这个错误。

File "F:/RUN/RUN/GetDictionary.py", line 11, in <module>
    print(df.loc[0:4])
  File "F:\anaconda\lib\site-packages\pandas\core\indexing.py", line 879, in __getitem__
    return self._getitem_axis(maybe_callable, axis=axis)
  File "F:\anaconda\lib\site-packages\pandas\core\indexing.py", line 1088, in _getitem_axis
    return self._get_slice_axis(key, axis=axis)
  File "F:\anaconda\lib\site-packages\pandas\core\indexing.py", line 1122, in _get_slice_axis
    indexer = labels.slice_indexer(
  File "F:\anaconda\lib\site-packages\pandas\core\indexes\base.py", line 4966, in slice_indexer
    start_slice, end_slice = self.slice_locs(start, end, step=step, kind=kind)
  File "F:\anaconda\lib\site-packages\pandas\core\indexes\base.py", line 5167, in slice_locs
    start_slice = self.get_slice_bound(start, "left", kind)
  File "F:\anaconda\lib\site-packages\pandas\core\indexes\base.py", line 5079, in get_slice_bound
    label = self._maybe_cast_slice_bound(label, side, kind)
  File "F:\anaconda\lib\site-packages\pandas\core\indexes\base.py", line 5031, in _maybe_cast_slice_bound
    self._invalid_indexer("slice", label)
  File "F:\anaconda\lib\site-packages\pandas\core\indexes\base.py", line 3267, in _invalid_indexer
    raise TypeError(
TypeError: cannot do slice indexing on Index with these indexers [0] of type int

Answer 1

您正在尝试使用大功率锤钻，而简单的螺丝刀更合适。 Pandas 确实是一个非常强大的库，它可以通过自动类型检测很好地处理 csv 文件，但您不需要所有这些：您只需要第一列的前 4 个字段。

只需在此处使用 csv 模块：

with open('data_v6/level3/topic_DIC.txt', 'a') as outfile:
    for root, dirs, files in os.walk("./data_v6/level3/"):
        count = 1
        for dir in dirs:
            print(dir)
            count= count+1
            print(count)
            with open('data_v6/level3/'+dir+'/tweets_topic.csv') as fd:
                rd = csv.reader(fd)
                try:
                    _ = next(rd)             # skip header line
                exception StopIteration:
                    print('data_v6/level3/'+dir+'/tweets_topic.csv is empty')
                    continue
                try:
                    for i in range(4):
                        try:
                            row = next(rd)
                            print(row[0], file=outfile)
                        except StopIteration:
                            break

将 CSV 文件处理为 txt 文件

1 个答案: