theano安装问题

WARNING (theano.configdefaults): g++ not available, if using conda: `conda install m2w64-toolchain`
D:Anaconda3libsite-packages	heanoconfigdefaults.py:560: UserWarning: DeprecationWarning: there is no c++ compiler.This is deprecated and with Theano 0.11 a c++ compiler will be mandatory
  warnings.warn("DeprecationWarning: there is no c++ compiler."
WARNING (theano.configdefaults): g++ not detected ! Theano will be unable to execute optimized C-implementations (for both CPU and GPU) and will default to Python implementations. Performance will be severely degraded. To remove this warning, set Theano flags cxx to an empty string.
WARNING (theano.tensor.blas): Using NumPy C-API based implementation for BLAS functions.

按照正常的顺序安装完(http://www.deeplearning.net/software/theano/install.html)，提示警告，如上。

于是，conda install m2w64-toolchain。

爆出一堆错误

于是，conda install libpython (https://blog.csdn.net/weixin_40849273/article/details/85266465)

更是一堆错误

Traceback (most recent call last):
  File "D:Anaconda3libconfigparser.py", line 1135, in _unify_values
    sectiondict = self._sections[section]
KeyError: 'blas'

During handling of the above exception, another exception occurred:

Traceback (most recent call last):
  File "D:Anaconda3libsite-packages	heanoconfigparser.py", line 168, in fetch_val_for_key
    return theano_cfg.get(section, option)
  File "D:Anaconda3libconfigparser.py", line 778, in get
    d = self._unify_values(section, vars)
  File "D:Anaconda3libconfigparser.py", line 1138, in _unify_values
    raise NoSectionError(section)
configparser.NoSectionError: No section: 'blas'

During handling of the above exception, another exception occurred:

Traceback (most recent call last):
  File "D:Anaconda3libsite-packages	heanoconfigparser.py", line 328, in __get__
    delete_key=delete_key)
  File "D:Anaconda3libsite-packages	heanoconfigparser.py", line 172, in fetch_val_for_key
    raise KeyError(key)
KeyError: 'blas.ldflags'

During handling of the above exception, another exception occurred:

Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
  File "D:Anaconda3libsite-packages	heano\__init__.py", line 124, in <module>
    from theano.scan_module import (scan, map, reduce, foldl, foldr, clone,
  File "D:Anaconda3libsite-packages	heanoscan_module\__init__.py", line 41, in <module>
    from theano.scan_module import scan_opt
  File "D:Anaconda3libsite-packages	heanoscan_modulescan_opt.py", line 60, in <module>
    from theano import tensor, scalar
  File "D:Anaconda3libsite-packages	heano	ensor\__init__.py", line 17, in <module>
    from theano.tensor import blas
  File "D:Anaconda3libsite-packages	heano	ensorlas.py", line 155, in <module>
    from theano.tensor.blas_headers import blas_header_text
  File "D:Anaconda3libsite-packages	heano	ensorlas_headers.py", line 987, in <module>
    if not config.blas.ldflags:
  File "D:Anaconda3libsite-packages	heanoconfigparser.py", line 332, in __get__
    val_str = self.default()
  File "D:Anaconda3libsite-packages	heanoconfigdefaults.py", line 1422, in default_blas_ldflags
    check_mkl_openmp()
  File "D:Anaconda3libsite-packages	heanoconfigdefaults.py", line 1262, in check_mkl_openmp
    """)
RuntimeError:
To use MKL 2018 with Theano either update the numpy conda packages to
their latest build or set "MKL_THREADING_LAYER=GNU" in your
environment.

于是，新建环境变量MKL_THREADING_LAYER=GNU，

似乎不管用

于是，conda update numpy

solved。

可以使用theano，但是当我尝试使用theano.scan时，

Process finished with exit code -1073741819 (0xC0000005)

墙内墙外多番查找，最终发现此贴可用！（https://blog.csdn.net/wangguan9527/article/details/82845409）

solved。