为什么即使在成功完成安装后仍会发生 DASK 数据框导入错误？

Question

我正在尝试使用 DASK。我点击了以下链接：

https://docs.dask.org/en/latest/install.html

我成功安装了所有东西。例如，我在我的虚拟环境中运行了以下命令：

conda install dask
python -m pip install "dask[complete]"
python -m pip install "dask[array]"       # Install requirements for dask array
python -m pip install "dask[dataframe]"   # Install requirements for dask dataframe
python -m pip install "dask[diagnostics]" # Install requirements for dask diagnostics
python -m pip install "dask[distributed]" # Install requirements for distributed dask

全部显示导入成功。但是，当我尝试导入 CSV 文件时，我的 Jupyter Notebook 或 Python 解释器中的以下命令会出现错误：

import dask.dataframe as dd


ImportError                               Traceback (most recent call last)
~/.conda/envs/latest/lib/python3.7/site-packages/dask/dataframe/__init__.py in <module>
      2     from ..base import compute
----> 3     from . import backends, dispatch, rolling
      4     from .core import (

~/.conda/envs/latest/lib/python3.7/site-packages/dask/dataframe/backends.py in <module>
      3 import numpy as np
----> 4 import pandas as pd
      5 from pandas.api.types import (

~/.conda/envs/latest/lib/python3.7/site-packages/pandas/__init__.py in <module>
     54 
---> 55 from pandas.core.api import (
     56     # dtype

~/.conda/envs/latest/lib/python3.7/site-packages/pandas/core/api.py in <module>
     14 from pandas.core.algorithms import factorize, unique, value_counts
---> 15 from pandas.core.arrays import Categorical
     16 from pandas.core.arrays.boolean import BooleanDtype

~/.conda/envs/latest/lib/python3.7/site-packages/pandas/core/arrays/__init__.py in <module>
     10 from pandas.core.arrays.integer import IntegerArray, integer_array
---> 11 from pandas.core.arrays.interval import IntervalArray
     12 from pandas.core.arrays.numpy_ import PandasArray, PandasDtype

~/.conda/envs/latest/lib/python3.7/site-packages/pandas/core/arrays/interval.py in <module>
     44 from pandas.core.indexers import check_array_indexer
---> 45 from pandas.core.indexes.base import ensure_index
     46 

~/.conda/envs/latest/lib/python3.7/site-packages/pandas/core/indexes/base.py in <module>
     76 from pandas.core.ops.invalid import make_invalid_op
---> 77 from pandas.core.strings import StringMethods
     78 

~/.conda/envs/latest/lib/python3.7/site-packages/pandas/core/strings/__init__.py in <module>
     29 
---> 30 from pandas.core.strings.accessor import StringMethods
     31 from pandas.core.strings.base import BaseStringArrayMethods

~/.conda/envs/latest/lib/python3.7/site-packages/pandas/core/strings/accessor.py in <module>
     15 import pandas._libs.lib as lib
---> 16 from pandas._typing import (
     17     DtypeObj,

ImportError: cannot import name 'DtypeObj' from 'pandas._typing' (/home/mdabdullahal.alamin/.conda/envs/latest/lib/python3.7/site-packages/pandas/_typing.py)

The above exception was the direct cause of the following exception:

ImportError                               Traceback (most recent call last)
/tmp/ipykernel_4116022/1671061512.py in <module>
----> 1 import dask.dataframe as dd
      2 # df  = dd.read_csv(file_name)
      3 # print(len(df))

~/.conda/envs/latest/lib/python3.7/site-packages/dask/dataframe/__init__.py in <module>
     58         '  python -m pip install "dask[dataframe]" --upgrade  # or python -m pip install'
     59     )
---> 60     raise ImportError(msg) from e

ImportError: Dask dataframe requirements are not installed.

Please either conda or pip install as follows:

  conda install dask                     # either conda install
  python -m pip install "dask[dataframe]" --upgrade  # or python -m pip install

我什至在 dask 安装后停用并重新激活虚拟环境。但它仍然不起作用并给出错误：

ImportError: Dask dataframe requirements are not installed.

Answer 1

这是一个非常奇怪的问题。我仍然不确定为什么会发生这种情况。我有一个 conda 虚拟环境，我在其中使用 Pandas 和 Numpy 进行数据分析，后来我在环境中安装了 DASK。

所有这些安装命令都成功了。但由于某种原因，它给了我错误。我重新启动并停用并重新激活环境，但它没有工作。后来我刚刚更新了 Conda 环境，它就开始工作了。

conda -y update --all

这解决了问题。安装 DASK 时它没有给我任何错误，但内部可能是某些库没有正确更新。