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ignoring_gravity
Asked: 2024-07-15 18:05:17 +0800 CST

如何将字符串附加到分块数组的每个元素？

  • 772

说我有

In [22]: import pyarrow as pa

In [23]: t = pa.table({'a': ['one', 'two', 'three']})

我想'_frobenius'将'a'

预期输出：

pyarrow.Table
a: string
----
a: [["one_frobenius","two_frobenius","three_frobenius"]]
python

2 个回答

  1. Best Answer

    您可以使用pyarrow.compute.binary_join_element_wise将固定字符串连接到每个元素：

    import pyarrow as pa
import pyarrow.compute as pc

t = pa.table({"a": ["one", "two", "three"]})

t = t.set_column(0, "a", pc.binary_join_element_wise(t["a"], "_frobenius", ""))

print(t)

    输出：

    pyarrow.Table
a: string
----
a: [["one_frobenius","two_frobenius","three_frobenius"]]
    • 3

  2. 您可以转换为 pandas Dataframe，修改字符串，然后再转换回来。例如，

    >>> import pyarrow as pa
>>> t = pa.table({'a': ['one', 'two', 'three']})
>>> df = t.to_pandas()
>>> df
       a
0    one
1    two
2  three
>>> df['a'] = df['a'] + '_frobenius'
>>> df
                 a
0    one_frobenius
1    two_frobenius
2  three_frobenius
>>> new_table = t.set_column(0, 'a', pa.array(df['a']))
>>> new_table
pyarrow.Table
a: string
----
a: [["one_frobenius","two_frobenius","three_frobenius"]]
    • 0

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