Python Pandas：如何仅读取前 n 行 CSV 文件？
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Python Pandas: How to read only first n rows of CSV files in?
提问by bensw
I have a very large data set and I can't afford to read the entire data set in. So, I'm thinking of reading only one chunk of it to train but I have no idea how to do it. Any thought will be appreciated.
我有一个非常大的数据集，我无法读取整个数据集。所以，我想只读取其中的一部分进行训练，但我不知道该怎么做。任何想法将不胜感激。
采纳答案by smci
If you only want to read the first 999,999 (non-header) rows:
如果您只想读取前 999,999（非标题）行：
read_csv(..., nrows=999999)
If you only want to read rows 1,000,000 ... 1,999,999
如果您只想读取行 1,000,000 ... 1,999,999
read_csv(..., skiprows=1000000, nrows=999999)
nrows: int, default None Number of rows of file to read. Useful for reading pieces of large files*
nrows：int，默认无要读取的文件行数。用于读取大文件片段*
skiprows: list-like or integer Row numbers to skip (0-indexed) or number of rows to skip (int) at the start of the file
skiprows: 类似列表或整数要跳过的行号（0-indexed）或要跳过的行数（int）在文件的开头
and for large files, you'll probably also want to use chunksize:
对于大文件，您可能还想使用 chunksize：
chunksize: int, default None Return TextFileReader object for iteration
chunksize: int, 默认 None 返回 TextFileReader 对象进行迭代
