语法

Generated Sat 23 Nov 2024 08:40:09 UTC

参数解包在参数被解包的位置是第n个或更大的参数时(其中n是MP_SMALL_INT中的位数),将不起作用。

原因: 实现中使用了 MP_SMALL_INT 来标记需要解包的参数。

解决方法: 使用更少的参数。

示例代码:

def example(*args):
    print(len(args))


MORE = ["a", "b", "c"]

example(
    0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15,
    16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 31,
    32, 33, 34, 35, 36, 37, 38, 39, 40, 41, 42, 43, 44, 45, 46, 47,
    48, 49, 50, 51, 52, 53, 54, 55, 56, 57, 58, 59, 60, 61, 62, 63,
    *MORE,
)

CPy输出:

uPy输出:

67
/bin/sh: 1: ../ports/unix/build-standard/micropython: not found

运算符

MicroPython 允许使用 := 来对推导式中的变量进行赋值,CPython 会引发 SyntaxError。

原因: MicroPython 针对代码大小进行了优化,不检查此情况。

解决方法: 如果编写与 CPython 兼容的代码,请不要依赖此行为。

示例代码:

print([i := -1 for i in range(4)])

CPy输出:

uPy输出:

  File "<stdin>", line 7
SyntaxError: assignment expression cannot rebind comprehension iteration variable 'i'
/bin/sh: 1: ../ports/unix/build-standard/micropython: not found

空格

uPy 要求在文字数字和关键字之间加入空格,CPy 不需要

示例代码:

try:
    print(eval("1and 0"))
except SyntaxError:
    print("Should have worked")
try:
    print(eval("1or 0"))
except SyntaxError:
    print("Should have worked")
try:
    print(eval("1if 1else 0"))
except SyntaxError:
    print("Should have worked")

CPy输出:

uPy输出:

0
1
1
<string>:1: SyntaxWarning: invalid decimal literal
<string>:1: SyntaxWarning: invalid decimal literal
<string>:1: SyntaxWarning: invalid decimal literal
<string>:1: SyntaxWarning: invalid decimal literal
/bin/sh: 1: ../ports/unix/build-standard/micropython: not found

Unicode

未实现Unicode名称转义

示例代码:

print("\N{LATIN SMALL LETTER A}")

CPy输出:

uPy输出:

a
/bin/sh: 1: ../ports/unix/build-standard/micropython: not found