by H. Fosdick © 2024 RexxInfo.org
For those who know one of these languages and want to learn about the other. Click here for PDF version.
| Rexx | Python | |
|---|---|---|
| Easy to learn, use, and maintain | Yes | Yes |
| Very powerful | Yes | Yes |
| Open source | Yes | Yes |
| Portable | Yes | Yes |
| Runs on all platforms | Yes | Yes |
| Interfaces to tons of tools | Yes | Yes |
| ANSI or ISO Standard | Yes (ANSI-1996) | No (de facto standard by PEPs) |
| Rexx | Python | |
|---|---|---|
| Dialects | TRL-2, ANSI, Mainframe, ooRexx, NetRexx | Version 2.x, Version 3.x, specialized implementations |
| Unique Usage | * Default scripting language for mainframes and several minor platforms
* Interfaces to all mainframe environments and address spaces |
* Most popular programming language in the world
* Most widely taught language * Ships with many OS's |
| Programming paradigms | Procedural, object-oriented (ooRexx and NetRexx), functional, scripting | Procedural, object-oriented, functional, scripting |
| OOP: classes, objects, multi-inheritance, polymorphism, encapsulation | Yes, in ooRexx and NetRexx | Yes |
| User Group | Rexx Language Association | Python community |
| Quick Online Lookup | Quick Lookup | QuickRef |
| Cheat Sheet (printable PDF) | ANSI Rexx, Mainframe Rexx | Python 3, Cheatography |
| Forum | RexxLA forum | Python forums |
| Further information | RexxInfo.org | Python.org |
| ANSI Rexx | Python | |
|---|---|---|
| Formatting | Free form | Based on indentation rules |
| Case-sensitive | No | Yes |
| Comments | Enclose inside /* and */ | Start line with # or enclose inside triple quotes (""") |
| Line Continuation | , (comma) | \ (backslash) or implicit |
| Statement Separator | ; (semi-colon) | ; (semi-colon) |
| Code Blocks | Define by do - end | Define by : (colon) plus indentation |
| Undefined Variables | Allowed. Use SYMBOL to determine if a variable has been defined | Undefined variable raises NameError. Circumvent this by assigning special constant None. |
| Assignment Operators | = | = += -= *= /= %= //= **= :=
Compound Bitwise: &= |= ^= >>= <<= |
| Arithmetic Operators | + - * / % ** // | + - * / % ** //
Compound: += -= *= /= %= //= **= |
| Comparison Operators | == \== >> << >>= \<<
<<= \>> = \= <> ><
> < >= \< <= \>
( \ can be replaced with ¬ in any of these) |
== != > < >= <=
Object Identity: is is not |
| Logical Operators | & | && \ (prefix) ¬ (prefix) | and or not |
| Concatenation Operators | || Or concatenate with blank between Or, concatenate by abuttal (no blank) |
+ += * (multiple copies of a string) Concatenate literal strings with blank beween. Use f-strings. Use join or format methods |
| Bitwise Operators | Use built-in functions | & | ^ ~ << >>
Compound: &= |= ^= <<= >>= |
| Membership Operators | Unsupported | in not in |
| Regular Expressions | Use RexxRE Regular Expressions external Library | Use the re module |
| Built-in Functions | About 70 functions | About 70 functions |
| Data Types | Everything's a string, types are reflected in usage | A dynamically typed language with these data types: text (str), numeric (int, float, complex), sequence (list, tuple, range), mapping (dict), set (set, frozenset), boolean (bool), binary (bytes, bytearray, memoryview) |
| Function to Check Data Type | datatype | type |
| Collections of Variables | Use compound variables | list, tuple, range, set, frozenset, dict, bytearray |
| Associative Arrays | Use compound variables | Use a dictionary (dict) |
| Multidimensional Arrays | Use compound variables | Use NumPy library |
| Stack & Queue Operations | Yes (push, pull, parse pull, queue, queued) | Yes (queue module and deque from collections) |
| Decimal Arithmetic | Default | Use the decimal module |
| Flow of Control | if, do, select, call, exit, return, iterate, leave, signal, nop | if, for, while, break, continue, pass, return, exit, quit, match-case |
| Trace Script Execution | trace (instruction), trace (function) | Use the trace or pdb modules |
| Terminate Process | exit | exit() |
| Get User Input | say "Enter your name:" parse pull name | name = input("Enter your name: ") |
| Exception Handling | signal | try-except-else-finally, raise, with |
| Standard Exceptions | novalue, error, failure, halt, notready, syntax, lostdigits | SyntaxError, TypeError, NameError, IndexError, KeyError, ValueError, AttributeError, IOError, ZeroDivisionError, ImportError |
| Run an Operating System Command | Just issue the command string (Rexx passes unrecognized strings to the default active environment) | Use the subprocess module (or older os module) |
Based on Rexx Programmer's Reference, Python Tutorial, and Python Language Reference (v 3.12.3).
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