tilelang/docs/programming_guides/python_compatibility.md

Python Compatibility

TileLang is a Python-embedded DSL, but not all Python syntax is supported inside TileLang DSL. This guide clarifies what works, what doesn't, and how to translate common Python patterns into TileLang equivalents. Specially, we focus on the kernel part (scripts inside with T.Kernel) semantics. For host-side semantics when using eager-style JIT, please stay tuned for our upcoming documentation.

The following codes use the conventional aliases:

import tilelang
import tilelang.language as T
from tilelang import jit

Control Flow & Loops

Python Feature	Supported	Notes / Alternative
for i in range(n)	✅	Maps to T.serial(n)
for i in range(a,b,s)	✅	Maps to T.serial(a, b, s)
for x in list	❌	Use index-based loop
while condition	✅
if / elif / else	✅
x if cond else y	✅	Ternary expression
break / continue	✅
enumerate() / zip()	❌

Data Access

Python Feature	Supported	Notes / Alternative
a[i] indexing	✅	Multi-dim indexing supported: a[i, j, k]
a[i:j] slicing	✅	Creates BufferRegion
a[-1] negative index	✅

Assignment & Arithmetic Operations

Python Feature	Supported	Notes / Alternative
x = expr	✅
+, -, *, /, %	✅	Maps to device-side arithmetic operations
+=, -=, *=, etc.	✅	Augmented assignment
a = b = c	❌	Use separate assignments

Functions & Classes

As a kernel script language, TileLang doesn't support functions or classes. You can use @T.macro to define reusable code blocks, which will be inlined at compile time like __device__ function.

Statements & Built-in Functions

Python Feature	Supported	Notes / Alternative
with	⚠️	Only T.Kernel, T.ws
assert	⚠️	Use T.device_assert or T.assert
print()	⚠️	Use T.print(); print works for Python expressions
len()	❌	Use buffer.shape[dim]
type(), isinstance()	❌