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CodeDeploy failing with error Errno::ENOEXEC with message Exec format error

I have a CodeDeploy which deploys application on Windows instances. I have a Python script which is running as part of ValidateService hooks. Below is the code I have in that script:
print("hello")
So, I have removed everything and just printing hello as part of this script. When this script is called by CodeDeploy I get below error:
My appspec.yml file:
...
ValidateService:
- location: scripts/verify_deployment.py
timeout: 900
I tried getting some help on Google but got nothing. Can someone please help me here.
Thanks

As Marcin already answered in a comment, I don't think you can simply run python scripts in CodeDeploy. At least not natively.
The error you see means that Windows does not know how to execute the script you have provided. AFAIK Windows can't run python natively (like most linux distros can).
I am not very accustomed to CodeDeploy, but given the example at https://github.com/aws-samples/aws-codedeploy-samples/tree/master/applications/SampleApp_Windows, I think you have to install python first.

After so much of investigations, I found my answer. The issue is little misleading, there is nothing to do with Code format or ENOEXEC. The issue was due to Python path. While executing my script, CodeDeploy was unable to find Python (Though I had already added python.exe in Environment variable path).
Also, I found that CodeDeploy is unable to execute .py file due to Python path issue. So, I created a PowerShell script and invoking Python script from there. Like below:
C:\Users\<username>\AppData\Local\Programs\Python\Python37-32\python.exe C:\Users\<username>\Documents\verify_deployment.py
It executed Python script successfully and gave me below output:
hello

Streaming and shell. Trivial query

The contents of the file a.py are:
a = input()
print(a)
and fearless.txt contains the string : pink floyd.
Now, when I simply type in %a.py < fearless.txt at the command prompt (windows), it gives an error "lost.stdin".
However, when I type %python a.py < fearless.txt, no error occurs.
I don't understand this, given that .py is a recognized extension and is run by python. Shouldn't then, both be equivalent?
Note I'm using the symbol % in place of the actual directory.
( Python version : 3.4.3:9b73f1c3e601 and winXP-32 bit. )

It depends a bit on how the .py files are registered. It should work when the py.exe launcher is set up correctly. You can verify this by looking up the following key in the registry: HKEY_CLASSES_ROOT\Python.File\shell\open\command. The default value should be "C:\WINDOWS\py.exe" "%1" %*.
You can also try using the following instead:
type fearless.txt | a.py
I just noticed that you are using Windows XP. The problem you are seeing might be because of an old Windows bug with redirection. It was said to be fixed at some point, but maybe XP was still partially affected. I suggest you to update your system anyway because Windows XP is no longer supported by Microsoft.

If this is on a Unix system (as I'm guessing it is), you'll need to have a shebang line at the top of the file to tell the kernel that this is a file whose contents need to be executed by the specified interpreter. The .py extension is just a detail and is not used to decide "how to run" the given program.
When you try to run the file without the shebang, it's being executed by your current shell and that's what's giving you the errors. Python doesn't even come into the picture.

Setting up a specific Python in Jenkins

I am quite new with configuring Jenkins or Python but I have to set up a unitary test in Jenkins. My program is in Python, but only works on Python 2.6 whereas the Jenkins version I should be using is 2.7, so I'm trying to set up Jenkins to set some environment variables so that it prepares launching the accurate Python for that specific test (it is part of a greater project that will successfully run several other tests that work well).
The idea I had was to set in the command to execute several environment variables like PATH, LD_LIBRARY_PATH and PYTHONPATH such as following in the "Execute shell" command line interpreter:
PYTHONPATH=/path/to/python2.6/lib:$PYTHONPATH
PATH=/path/to/python2.6/bin:$PATH
LD_LIBRARY_PATH=/path/to/python2.6/lib:$LD_LIBRARY_PATH
... however, it was still calling the wrong version of Python. Therefore, I forced these variables to:
PYTHONPATH=/path/to/python2.6/lib
PATH=/path/to/python2.6/bin
LD_LIBRARY_PATH=/path/to/python2.6/lib
... and I still get errors because the old version of Python is called instead, even if it should not appear in the PATH ... It appears Jenkins will remember the location of the old libraries however and will try loading them first.
How would I correctly set the environment in a "subproject" in Jenkins so that I can call a different version of Python?
Thank you and best regards,
~Stéphane

If you want your program to run with a specific version of the python interpreter, you indicate it in the shebang
#!/usr/bin/python2.6
#your code here

What i did in my Jenkins shell script using a specific python version was something like this when calling my unit test:
python3 src/test/unit_test.py
I was using it to use Python 3.X but it should work with 2.6 as well using:
python2.6 src/test/unit_test.py

Stupid me... I was indeed doing things correctly, I just had a part of my code that was overriding the PYTHONPATH value, so the solution I had found previously was good.
FYI, I modified my shebang, if it's of any help to anyone ;)

Some powershell cmd-lets not available if run from python?

So this is an unusual one, and perhaps I am simply missing the obvious, but I have the following python code that creates a powershell script and runs it.
# Create the PowerShell file
f = open("getKey.ps1", "w")
f.write('$c = Get-BitlockerVolume -MountPoint C:\n')
f.write('$c.KeyProtector[1].RecoveryPassword | Out-File C:\\Temp\\recovery.key\n')
# Invoke Script
startPS = subprocess.Popen([r'C:\Windows\system32\WindowsPowerShell\v1.0\powershell.exe',
'-ExecutionPolicy', 'Unrestricted', './getKey.ps1'], cwd=os.getcwd())
result = startPS.wait()
When this is run, it gives me the following error:
The term 'Get-BitlockerVolume' is not recognized as the name of a cmdlet, function, script file, or operable program.
However, if I then go and manually run the generated script, it works perfectly. To add to the oddity, if I run the same command exactly as above ie:
C:\Windows\system32\WindowsPowerShell\v1.0\powershell.exe -ExecutionPolicy Unrestricted ./getKey.ps1
it also works exactly as expected.
Clearly, the above error is a powershell error, so it is successfully running the script. It almost seems like powershell somehow knows that this is being run from python and has some restricted library of commands when a script is run from a particular source. I grant that that idea makes no real sense, but it's certainly how things appear.
I don't think this is a permissions issue, because when you run the same command from an unelevated powershell prompt, you get an Access is denied type error, rather than a command doesn't exist kind of error.
Anyway, any help would be greatly appreciated!
Edits
Edit: New evidence to help figure this out:
It's definitely an issue of cmdlets being loaded properly. If I programmatically run a script to dump the list of all available commands to a text file, it is only about 2/3's as big as if I do so through a powershell prompt directly

I bet Python is running as a 32-bit process on 64-bit Windows. In this case, you'll end up running 32-bit PowerShell, which in practice is a Bad Thing since many PowerShell modules depend on native binaries that may not have 32-bit equivalents. I hit this with IIS Manager commandlets--the commandlets themselves are registered in 32-bit PowerShell, but the underlying COM objects they rely on are not.
If you need to run 64-bit PowerShell from a 32-bit process, specify the path as %SystemRoot%\SysNative\WindowsPowerShell\v1.0\PowerShell.exe instead of System32.
System32 is actually virtualized for 32-bit processes and refers to the 32-bit binaries in %SystemRoot%\SysWow64. This is why your paths (and PSMODULEPATH) will look the same, but aren't. (SysNative is also a virtualized path that only exists in virtualized 32-bit processes.)

Adding to what #jbsmith said in the comment, also check to make sure that the environment variable that PowerShell relies on to know where it's modules are is populated correctly when python starts the process.
%PSMODULEPATH% is the environment variable in question, and it works the same way the %PATH% variable does, multiple directories separated by ;. Based on what you say your observed behavior is, it seems that you are using PowerShell 3.0, and cmdlet autoloading is in effect.

The solution here: Run a powershell script from python that uses Web-Administration module got me the cmdlet I needed, however there are still missing cmdlets even when using this method. I'm still at a loss as to why some are loaded and others are not, but for the time being, my script does what I need it to and I can't spend any more time to figure it out.
For reference here is the code that worked for me
startPS = subprocess.Popen([r'C:\Windows\sysnative\cmd.exe', '/c', 'powershell',
'-ExecutionPolicy', 'Unrestricted', './getKey.ps1'], cwd=os.getcwd())

I had the same issue, and it was simply that the BitLocker feature was not installed, hence the module wasn't present.
I fixed it by installing the Bitlocker feature:
Windows Server:
Install-WindowsFeature BitLocker -IncludeAllSubFeature -IncludeManagementTools -Restart
Windows Desktop:
Enable-WindowsOptionalFeature -Online -FeatureName BitLocker -All

How to properly use PyDev with two different Python versions with scripts that are recalling other python scripts?

The story began with a very strange error while I was running my script from PyDev. Running the same script from outside will not encounter the same problem.
Fatal Python error: Py_Initialize: can't initialize sys standard streams
File "C:\Python26\lib\encodings\__init__.py", line 123
raise CodecRegistryError,\
^
SyntaxError: invalid syntax
This application has requested the Runtime to terminate it in an unusual way.
Please contact the application's support team for more information.
I was able to find why this is happening: In PyDev I use two different Python versions: 3.1 that is the default installation and 2.6 as the alternative one.
My Windows Environment does not contains PYTHONHOME, CLASSPATH, PYTHONPATH but PyDev does add them.
Now the problem is at one stage my python script does execute another python script using os.system(python second.py) and the second script will fail with the above error.
Now I'm looking to find a way to prevent this issue, issue that is happening because it will run the execute the default python using the settings for the non-default one (added by PyDev).
I do not want to change the standard call (python file.py) but I want to be able to run my script from pydev without problem and being able to use default or alternative python environment.
Any ideas?

I found a solution that seams acceptable specially because it will not interfere with running the scripts on other systems, just to run python -E second.py - this will force Python to ignore PYTHON* environment variables.

I may not be understanding this quite right, but I think you're invoking a script from pydev that works okay, but this script executes another script which requires a different version.
While this would unfortunately be installation-specific, you could use os.system("c:\absolute\path\to\proper\version\of\python.exe second.py").
If PyDev is setting up conflicting environmental variables, you may want to look into subprocess over os.system.
http://docs.python.org/library/subprocess.html#using-the-subprocess-module
This will allow you to invoke a process with a handle, so you can optionally wait for it to terminate. It will also allow you to pass environment variables upon execution.

I believe your call should be:
import sys
os.system(sys.executable+ ' second.py')
So that you guarantee you're using the same interpreter you're currently running and not launching the other one (or did you really mean to use the other interpreter?)