Pyhton code embedding in STATA ado program

[Amit Narnoli]

Dear All,

I am trying to generate SHA256 equivalent of a string using python code using the following code:

local string = "AMIT"
version 18.0
python:
import hashlib
from sfi import Macro

# Get the string from Stata
fixed_string = r""" `string' """
fixed_string = fixed_string.strip('"\' ') # Remove any extra quotes

def generate_sha256(input_string):
    input_bytes = input_string.encode('utf-8')  # Convert input to bytes
    hash_obj = hashlib.sha256()  # Create SHA-256 hash object
    hash_obj.update(input_bytes)  # Compute hash
    return hash_obj.hexdigest()  # Return hexadecimal hash

# Generate SHA-256 hash
sha256_hash = generate_sha256(fixed_string)

# Store result in Stata macro
Macro.setLocal("sha256_hash", sha256_hash)

print(f"Input String: {fixed_string}")
print(f"SHA256: {sha256_hash}")
end

This code works perfectly fine inside a dofile. But when I try to use this file inside the following ado program, and pass the value of string from stata ado block to python block, this gives an error:

program define genSHA2
    version 18.0
    syntax, STRing(str)
    di "`string'"
end


version 18.0
python:
import hashlib
from sfi import Macro

# Get the string from Stata
fixed_string = r""" `string' """
fixed_string = fixed_string.strip('"\' ')  # Remove any extra quotes

def generate_sha256(input_string):
    input_bytes = input_string.encode('utf-8')  # Convert input to bytes
    hash_obj = hashlib.sha256()  # Create SHA-256 hash object
    hash_obj.update(input_bytes)  # Compute hash
    return hash_obj.hexdigest()  # Return hexadecimal hash

# Generate SHA-256 hash
sha256_hash = generate_sha256(fixed_string)

# Store result in Stata macro
Macro.setLocal("sha256_hash", sha256_hash)

print(f"Input String: {fixed_string}")
print(f"SHA256: {sha256_hash}")
end

di "`sha256_hash'"

Can anyone please help me understand what is the error in this ado program and how to fix that?

Thank you.

Best regards,
Amit

[daniel klein]

There are some misunderstandings regarding the scope of local macros, how ado-files generally work, and how Python code works within ado-files. I won't go through your code in detail. The key idea is that your Python code should be wrapped in one or more functions and your program must explicitly call the Python function(s). Here is a basic layout as a proof of concept:

program define py_sha256
    
    version 18
    
    python : py_sha256("0")
    
    display `"`0'"'
    
end


version 18

python :

import hashlib
from sfi import Macro

def py_sha256(lmname):
    input_string = Macro.getLocal(lmname).encode("utf-8")
    hash_obj = hashlib.sha256()
    hash_obj.update(input_string)
    Macro.setLocal(lmname,hash_obj.hexdigest())

end

Save this as an py_sha256.ado where Stata can find it, then call

. py_sha256 Amit
105a112c81ce60e646c007e98655b7caa27d9e6f36a7ba9584e406dd400e15ff