Python Differences

Scriptling is inspired by Python but has intentional limitations for embedded scripting. This page documents what’s NOT supported and key differences.

Python Features NOT Supported

Language Features

Built-in Functions NOT Supported

Standard Library NOT Included

Exception Handling Differences

Other Differences

Supported Python 3 Features

Scriptling does support:

• ✅ Classes with single inheritance and super()
• ✅ Dunder methods: __str__, __repr__, __len__, __bool__, __eq__, __lt__, __gt__, __le__, __ge__, __ne__, __contains__, __iter__, __next__, __enter__, __exit__
• ✅ Lambda functions and closures
• ✅ List comprehensions and dict comprehensions
• ✅ Iterators (range, map, filter, enumerate, zip)
• ✅ Dictionary views (keys(), values(), items())
• ✅ F-strings and .format()
• ✅ True division (/ always returns float)
• ✅ Set literals {1, 2, 3} and set operations
• ✅ Try/except/finally error handling
• ✅ Multiple assignment and tuple unpacking
• ✅ Extended unpacking with *
• ✅ Variadic arguments (*args)
• ✅ Keyword arguments (**kwargs)
• ✅ Default parameter values
• ✅ Conditional expressions (ternary operator)
• ✅ Augmented assignment (+=, -=, etc.)
• ✅ Slice notation with step ([start:stop:step])
• ✅ is and is not operators
• ✅ in and not in operators
• ✅ Bitwise operators (&, |, ^, ~, <<, >>)
• ✅ Boolean operators with short-circuit evaluation
• ✅ Assert statements (assert condition, "message")
• ✅ Context managers (with / as, __enter__ / __exit__)
• ✅ String methods (most Python string methods)
• ✅ List, dict, set methods (most Python methods)
• ✅ @property, @staticmethod, @classmethod decorators
• ✅ for/else and while/else
• ✅ match/case with OR patterns (case 1 | 2 | 3:)

Key Behavioral Differences

HTTP Response Object

Python requests returns attributes, Scriptling returns an object:

# Python
response.json()  # Method call
response.text    # Attribute

# Scriptling
json.loads(response.body)  # Parse manually
response.status_code       # Attribute
response.body              # Attribute (not response.text)

Library Import

Scriptling uses dynamic imports that load libraries on first use:

# Both work the same
import json
import requests

# Library is loaded when first accessed
data = json.loads('{"key": "value"}')

Default Timeout

HTTP requests have a default 5-second timeout:

# Python - no default timeout (hangs forever)
response = requests.get("https://slow-api.com")

# Scriptling - 5 second default
response = requests.get("https://slow-api.com")  # Times out after 5s

# Explicit timeout
response = requests.get("https://slow-api.com", {"timeout": 30})

No Implicit Type Coercion

# Python - implicit conversion
"Count: " + 5  # Error in Python 3, worked in Python 2

# Scriptling - explicit conversion required
"Count: " + str(5)  # "Count: 5"

File System Access

File access is sandboxed by default:

# Python - full file system access
f = open("/etc/passwd", "r")

# Scriptling - requires os library with allowed paths
import os
# Only works if /etc is in allowed paths
content = os.read_file("/etc/passwd")

Error vs Exception

Scriptling distinguishes between fatal Errors and catchable Exceptions:

# Errors cannot be caught
try:
    x = undefined_variable  # NameError (fatal)
except:
    print("Won't get here")  # Never runs

# Exceptions can be caught
try:
    raise "Custom error"  # Exception
except:
    print("Caught!")  # This runs

Migration Tips

From Python to Scriptling

1. Replace open() with os library (with works for custom context managers, but there is no built-in open()):

   # Python
   with open("file.txt") as f:
       content = f.read()
   
   # Scriptling
   import os
   content = os.read_file("file.txt")

2. Use explicit JSON handling:

   # Python
   data = response.json()
   
   # Scriptling
   import json
   data = json.loads(response.body)

3. Avoid async/await:

   # Python
   async def fetch():
       response = await client.get(url)
   
   # Scriptling - synchronous only
   def fetch():
       return requests.get(url)

4. Use match/case instead of complex if/elif:

   # Both work
   if status == 200:
       handle_success()
   elif status == 404:
       handle_not_found()
   
   match status:
       case 200:
           handle_success()
       case 404:
           handle_not_found()

See Also

• Syntax Rules - Scriptling syntax
• Functions - Function parameters
• Error Handling - Error vs Exception
• Classes - Class limitations