Chapter4 Building Good Training Sets – Data Preprocessing 4.1 Dealing with missing data 如何判断数据框内的数据是否有空值呢? import pandas as pd from io import StringIO csv_data = '''A, B, C, D 1.0,2.0,3.0,4.0 5.0,6.0,,8.0 10.0,11.0,12.0,''' df = pd.read_csv(StringIO(…