Fix input_dtype errors in pre-2.0 keras model H5FS files

fix_keras_model.py

# Usage: fix_keras_model.py old_model.h5 new_model.h5
import h5py
import shutil
import json
import sys

input_model_path = sys.argv[1]
output_model_path = sys.argv[2]
shutil.copyfile(input_model_path, output_model_path)

with h5py.File(output_model_path, "r+") as out_h5:
  v = out_h5.attrs.get("model_config")
  config = json.loads(v)
  for i, l in enumerate(config["config"]["layers"]):
    dtype = l["config"].pop("input_dtype", None)
    if dtype is not None:
      l["config"]["dtype"] = dtype

  new_config_str = json.dumps(config)
  out_h5.attrs.modify("model_config", new_config_str)

# Check that it worked.
from keras.models import load_model
load_model(output_model_path)

Doesn't work for Python 3 unfortunately :/

To make it work with Python3:

1. Replace
   v = out_h5.attrs.get("model_config")
   with
   v = out_h5.attrs.get("model_config").decode("utf-8")

2. Replace
   new_config_str = json.dumps(config)
   with
   new_config_str = json.dumps(config).encode("utf-8")

This is my code.

import h5py
import shutil
import json
import sys

input_model_path = 'age_model.h5'
output_model_path = 'modify_Age.model.h5'
shutil.copyfile(input_model_path, output_model_path)

with h5py.File(output_model_path, "r+") as out_h5:
    v = out_h5.attrs.get("model_config").decode("utf-8")
    config = json.loads(v)
    for i, l in enumerate(config["config"]["layers"]):
        dtype = l["config"].pop("input_dtype", None)
        if dtype is not None:
            l["config"]["dtype"] = dtype

    new_config_str = json.dumps(config).encode("utf-8")
    out_h5.attrs.modify("model_config", new_config_str)

# Check that it worked.
from keras.models import load_model
load_model(output_model

It fires following error,

for i, l in enumerate(config["config"]["layers"]):

TypeError: list indices must be integers or slices, not str