sys – Specific System Functions

The system module provides functions and variables related to the MicroPython operating environment.

This module implements the corresponding CPython a subset of modules, as follows. See the CPython document for details: sys

Functions

sys.exit(retval=0)

Terminate the current program with the given exit code. On this basis, this function is upgraded to SystemExit . If a parameter is given, its value is given as a parameter SystemExit .

sys.print_exception(exc, file=sys.stdout)

By tracing back to class object file（or sys.stdout by defauit）to print exceptions.

differences with CPython

This traceback simplified versions of functions that appear in CPython modules. 。The difference with traceback.print_exception() , This function only uses exception values instead of exception types, exception values and backtracking objects; the file parameter should be positional; other parameters are not supported. traceback CPython compatible modules can be found micropython-lib 。

Constant

sys.argv

Variable parameter list of current program launch.

sys.byteorder

Byte order of the system（ little or big ）。

sys.implementation

Objects that contain information about the current Python implementation. For MicroPython，it has the following attributes：

• name - string “micropython”
• version - Tuple (primary, secondary, micro), e.g. (1, 7, 0)

This method is recommended to identify MicroPython on different platforms.

Example:

>>> print(sys.implementation)
(name='micropython', version=(1, 9, 1))

sys.maxsize

The maximum integer type value that can be saved on the current platform，If it is less than the platform maximum. （For MicroPython ports without INT support）。

This attribute is useful for detecting the “bits” (32-bit, 64 bit, etc.) of the platform. It is not recommended to directly compare this property with a value, but to calculate the number of digits in it :::

bits = 0
v = sys.maxsize
while v:
    bits += 1
    v >>= 1
if bits > 32:
    # 64-bit (or more) platform
    ...
else:
    # 32-bit (or less) platform
    # Note that on 32-bit platform, value of bits may be less than 32
    # (e.g. 31) due to peculiarities described above, so use "> 16",
    # "> 32", "> 64" style of comparisons.

sys.modules

Loaded module dictionary. In some migration versions, it may not be included in built-in modules.

sys.path

List of variable directories to search for import modules.

sys.platform

Gets the MicroPython operating platform.

sys.stderr

Standard error stream

sys.stdin

Standard input stream

sys.stdout

Standard output stream

sys.version

returns MicroPython language version, string

sys.version_info

returns MicroPython language version, restructured tuple