pandas分块处理较大csv

import pandas as pd

def process(input_path, output_path):
    for i, df in enumerate(pd.read_csv(input_path, chunksize=100000)):
        df = _process(df)
        mode = "a" if i != 0 else "w"
        header = True if i == 0 else None
        df.to_csv(output_path, index=None, mode=mode, header=header)