Aftermodifying the mbed configuration files so that uses C++11,error:/usr/bin/python3 returned error

My system: ubuntu 18.04
board:STM32F746G
tensorflow version:2.3.0
python version: 3.8
When I followed this project https://github.com/tensorflow/tensorflow/tree/master/tensorflow/lite/micro/examples/hello_world#deploy-to-STM32F746
After I finished the whole process, it was successful, but when I run this command to use C++11
‘’‘’‘’’
python3 -c ‘import fileinput, glob;
for filename in glob.glob(“mbed-os/tools/profiles/*.json”):
for line in fileinput.input(filename, inplace=True):
print(line.replace(“"-std=gnu++98"”,“"-std=c++11", "-fpermissive"”))’

‘’‘’‘’
The error shows below:

Blockquote
mbed] Working path “~/tensorflow/tensorflow/lite/micro/tools/make/gen/disco_f746ng_cortex-m4_default/prj/hello_world/mbed” (library)
[mbed] Program path “~/tensorflow/tensorflow/lite/micro/tools/make/gen/disco_f746ng_cortex-m4_default/prj/hello_world/mbed”
WARNING: MBED_ARM_PATH set as environment variable but doesn’t exist
Traceback (most recent call last):
File “~/tensorflow/tensorflow/lite/micro/tools/make/gen/disco_f746ng_cortex-m4_default/prj/hello_world/mbed/mbed-os/tools/make.py”, line 421, in
main()
File “~/tensorflow/tensorflow/lite/micro/tools/make/gen/disco_f746ng_cortex-m4_default/prj/hello_world/mbed/mbed-os/tools/make.py”, line 354, in main
build_profile=extract_profile(parser, options, internal_tc_name),
File “~/tensorflow/tensorflow/lite/micro/tools/make/gen/disco_f746ng_cortex-m4_default/prj/hello_world/mbed/mbed-os/tools/options.py”, line 128, in extract_profile
contents = load(open(filename))
File “/usr/lib/python3.8/json/init.py”, line 293, in load
return loads(fp.read(),
File “/usr/lib/python3.8/json/init.py”, line 357, in loads
return _default_decoder.decode(s)
File “/usr/lib/python3.8/json/decoder.py”, line 337, in decode
obj, end = self.raw_decode(s, idx=_w(s, 0).end())
File “/usr/lib/python3.8/json/decoder.py”, line 355, in raw_decode
raise JSONDecodeError(“Expecting value”, s, err.value) from None
json.decoder.JSONDecodeError: Expecting value: line 1 column 1 (char 0)
[mbed] ERROR: “/usr/bin/python3” returned error.
Code: 1
Path: “~/tensorflow/tensorflow/lite/micro/tools/make/gen/disco_f746ng_cortex-m4_default/prj/hello_world/mbed”
Command: “/usr/bin/python3 -u ~/tensorflow/tensorflow/lite/micro/tools/make/gen/disco_f746ng_cortex-m4_default/prj/hello_world/mbed/mbed-os/tools/make.py -t GCC_ARM -m DISCO_F746NG --source . --build ./BUILD/DISCO_F746NG/GCC_ARM”
Tip: You could retry the last command with “-v” flag for verbose output