← index #18091Issue #17075
Off-topic · high · value 4.318
QUERY · ISSUE

print output redirection not working as in Python.

openby beetlegiggopened 2025-09-17updated 2025-09-19
bug

Port, board and/or hardware

raspberry pico2w

MicroPython version

MicroPython v1.26.0 on 2025-08-09; Raspberry Pi Pico 2 W with RP2350

Reproduction

# print redirection test
import sys
proper_stdout = sys.stdout       # save original
log = open('out.txt', 'w')
sys.stdout = log                 # redirect stdout            

print('hello')
print('wheres my print')

log.close()
sys.stdout = proper_stdout      # revert redirect

print('back to the future')
print('so whats in the out.txt file?')

read_log = open('out.txt', 'r')
for line in read_log:
    print(line)
read_log.close()    

Expected behaviour

The sys.stdout would be redirected to the 'log' file (out.txt) and the following print two print statement contents would be directed to the out.txt file.

Observed behaviour

Traceback (most recent call last):
File "<stdin>", line 5, in <module>
AttributeError: 'module' object has no attribute 'stdout'

line 5 is:
sys.stdout = log

Additional Information

This code snippet works as expected in Python.

Code of Conduct

Yes, I agree

CANDIDATE · ISSUE

Syntax Error when using multiline f-strings on RP2040 with MicroPython v1.23.0

openby kpg141260opened 2025-04-04updated 2025-10-03
bugproposed-close

Port, board and/or hardware

RP2040 Raspberry Pi Pico

MicroPython version

MicroPython Version: v1.23.0 (2024-06-02)
RP2040 Platform: Raspberry Pi Pico
Python Version: MicroPython (RP2040)
Firmware: v1.23.0
Hardware: Raspberry Pi Pico (RP2040)

Reproduction

msg = (
    f'One ' 
    f'Two ' 
    f'Three'
)

print(msg)

Expected behaviour

The above code should print the concatenated string One Two Three without any syntax errors, similar to how it works in standard Python environments.

Observed behaviour

SyntaxError: invalid syntax

Additional Information

This issue persists even when re-typing the code, leading me to suspect it might be an issue with the way multiline f-strings are handled on this particular platform.

The issue can be resolved by concatenating the f-strings manually using +:

msg = (
    f'One ' +
    f'Two ' +
    f'Three'
)

print(msg)

Workaround:

Using string concatenation (as shown above) works, but this is not as elegant and adds unnecessary complexity compared to expected behaviour.

What else I have tried:

Testing with other Python environments (such as standard Python 3.x) shows that the multiline f-string works as expected.

This issue does not occur with simpler, single-line f-strings.
Ensuring no invisible characters or incorrect syntax in the code.

Code of Conduct

Yes, I agree

Keyboard

j / / n
next pair
k / / p
previous pair
1 / / h
show query pane
2 / / l
show candidate pane
c
copy suggested comment
r
toggle reasoning
g i
go to index
?
show this help
esc
close overlays

press ? or esc to close

copied