这是索引列,请通过传递
index=False以免将其写出,请参阅文档
例:
In [37]:df = pd.Dataframe(np.random.randn(5,3), columns=list('abc'))pd.read_csv(io.StringIO(df.to_csv()))Out[37]: Unnamed: 0 a b c00 0.109066 -1.112704 -0.54520911 0.447114 1.525341 0.31725222 0.507495 0.137863 0.88628333 1.452867 1.888363 1.16810144 0.901371 -0.704805 0.088335与之比较:
In [38]:pd.read_csv(io.StringIO(df.to_csv(index=False)))Out[38]: a b c0 0.109066 -1.112704 -0.5452091 0.447114 1.525341 0.3172522 0.507495 0.137863 0.8862833 1.452867 1.888363 1.1681014 0.901371 -0.704805 0.088335
您还可以选择
read_csv通过传递
index_col=0以下内容来判断第一列是索引列:
In [40]:pd.read_csv(io.StringIO(df.to_csv()), index_col=0)Out[40]: a b c0 0.109066 -1.112704 -0.5452091 0.447114 1.525341 0.3172522 0.507495 0.137863 0.8862833 1.452867 1.888363 1.1681014 0.901371 -0.704805 0.088335



