如何迭代DataTable中帧的行

Question

对于pandas，我通常使用itertuples或iterrows迭代数据帧的行。如何在PythonDataTable的框架上进行这种迭代

我需要的熊猫迭代示例：

for row in df_.itertuples():
    print(row)

Answer 1

从documentation for DataTables开始：

A Frame is column-oriented in the sense that internally the data is stored separately for each column. Each column has its own name and type. Types may be different for different columns but cannot vary within each column.

也就是说，您可以按如下方式迭代行：

from datatable import dt, f, by, g, join, sort, update, ifelse

data = {"A": [1, 2, 3, 4, 5],
        "B": [4, 5, 6, 7, 8],
        "C": [7, 8, 9, 10, 11],
        "D": [5, 7, 2, 9, -1]}

# datatable
DT = dt.Frame(data)

# select single row
print(DT[2, :])

# Select several rows by their indices
print(DT[[2,3,4], :])

# Select a slice of rows by position
print(DT[2:5, :])

# Select rows on multiple conditions, using OR
print(DT[(f.A>3) | (f.B<5), :])

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有关更多行迭代示例以及与Pandas DataFrame的比较，请查看this official page。如果你有一些问题，你可以在DataTable official github repo上提出