Python – How to change Keras backend (where’s the json file)

command linekeraspythontheano

I have installed Keras, and wanted to switch the backend to Theano. I checked out this post, but still have no idea where to put the created json file. Also, below is the error I got when running import keras in Python Shell:

Using TensorFlow backend.

Traceback (most recent call last): File "", line 1, in

import keras File "C:\Python27\lib\site-packages\keras__init__.py", line 2, in
from . import backend File "C:\Python27\lib\site-packages\keras\backend__init__.py", line 64, in

from .tensorflow_backend import * File "C:\Python27\lib\site-packages\keras\backend\tensorflow_backend.py",
line 1, in
import tensorflow as tf ImportError: No module named tensorflow

When running python -c "import keras; print(keras.__version__)" from Windows command line, I got:

Using TensorFlow backend. Traceback (most recent call last): File
"", line 1, in File
"C:\Python27\lib\site-packages\keras__init__.py", line 2, in
from . import backend File "C:\Python27\lib\site-packages\keras\backend__init__.py", line 64, in

from .tensorflow_backend import * File "C:\Python27\lib\site-packages\keras\backend\tensorflow_backend.py",
line 1, in
import tensorflow as tf ImportError: No module named tensorflow

Can someone please help? Thanks!

Best Answer

After looking at keras sources (this place):

Start up your python-binary and do the following

import os
print(os.path.expanduser('~'))
# >>> C:\\Users\\Sascha'  # will look different for different OS

This should be the base-directory
Keras will build an folder .keras there where keras.json resides (if it was already created). If it's not there, create it there
Example: C:\\Users\\Sascha\\.keras\\keras.json'

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Python – How to check whether a file exists without exceptions

If the reason you're checking is so you can do something like if file_exists: open_it(), it's safer to use a try around the attempt to open it. Checking and then opening risks the file being deleted or moved or something between when you check and when you try to open it.

If you're not planning to open the file immediately, you can use os.path.isfile

Return True if path is an existing regular file. This follows symbolic links, so both islink() and isfile() can be true for the same path.

import os.path
os.path.isfile(fname)

if you need to be sure it's a file.

Starting with Python 3.4, the pathlib module offers an object-oriented approach (backported to pathlib2 in Python 2.7):

from pathlib import Path

my_file = Path("/path/to/file")
if my_file.is_file():
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To check a directory, do:

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Python – How to copy a file in Python

shutil has many methods you can use. One of which is:

from shutil import copyfile
copyfile(src, dst)

# 2nd option
copy(src, dst)  # dst can be a folder; use copy2() to preserve timestamp

Copy the contents of the file named src to a file named dst. Both src and dst need to be the entire filename of the files, including path.
The destination location must be writable; otherwise, an IOError exception will be raised.
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Best Answer

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