3.7 KiB
sys
-- system specific functions
sys
python:sys
.
Functions
exit(retval=0)
Terminate current program with a given exit code. Underlyingly, this function raise as SystemExit exception. If an argument is given, its value given as an argument to SystemExit.
print_exception(exc, file=sys.stdout)
Print exception with a traceback to a file-like object file (or sys.stdout by default).
Difference to CPython
This is simplified version of a function which appears in the
traceback
module in CPython. Unlike
traceback.print_exception()
, this function takes just
exception value instead of exception type, exception value, and
traceback object; file argument should be positional; further
arguments are not supported. CPython-compatible traceback
module can be found in micropython-lib.
Constants
argv
A mutable list of arguments the current program was started with.
byteorder
The byte order of the system ("little"
or
"big"
).
implementation
Object with information about the current Python implementation. For MicroPython, it has following attributes:
- name - string "micropython"
- version - tuple (major, minor, micro), e.g. (1, 7, 0)
This object is the recommended way to distinguish MicroPython from other Python implementations (note that it still may not exist in the very minimal ports).
Difference to CPython
CPython mandates more attributes for this object, but the actual useful bare minimum is implemented in MicroPython.
maxsize
Maximum value which a native integer type can hold on the current platform, or maximum value representable by MicroPython integer type, if it's smaller than platform max value (that is the case for MicroPython ports without long int support).
This attribute is useful for detecting "bitness" of a platform (32-bit vs 64-bit, etc.). It's recommended to not compare this attribute to some value directly, but instead count number of bits 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.
modules
Dictionary of loaded modules. On some ports, it may not include builtin modules.
path
A mutable list of directories to search for imported modules.
platform
The platform that MicroPython is running on. For OS/RTOS ports, this
is usually an identifier of the OS, e.g. "linux"
. For
baremetal ports it is an identifier of a board, e.g.
"pyboard"
for the original MicroPython reference board. It
thus can be used to distinguish one board from another. If you need to
check whether your program runs on MicroPython (vs other Python
implementation), use sys.implementation
instead.
stderr
Standard error stream.
stdin
Standard input stream.
stdout
Standard output stream.
version
Python language version that this implementation conforms to, as a string.
version_info
Python language version that this implementation conforms to, as a tuple of ints.