maximum recursion depth exceeded while calling a python object

Question

Problem :

I am getting below error

maximum recursion depth exceeded while calling a python object

Answer 1

Python lacks the tail recursion optimizations which is common in functional languages like lisp. In Python, recursion is limited to 999 calls 

1) You can change the recursion limit with sys.setrecursionlimit(n) until the maximum allowed for your platform:

sys.setrecursionlimit(limit):

2) You can try to convert the algorithm from recursive to iterative. If recursion depth is bigger than allowed by your platform, it is the only way to fix the problem. 

Further Readings:

https://github.com/python/typing/issues/523

Answer 2

You'll trace flashbdev.py in the source tree esp826/modules. It would appear to be the low level driver for the flash memory - my guess is that the readblocks system is being named recursively probably owing to re-entrant code. At the time you change parameters is there a situation where a timer callback implements prior another has finished accessing a file?

Accessing files in an interrupt handler is a bad idea since file access times are not deterministic. More, code in interrupt handlers such as timer callbacks must be designed to implement fast.

I would possibly avoid employing a timer and only run a loop which achieves its timing like this:

import utime
while True:
	tstart = utime.ticks_ms()
	# do all your stuff
	delta = 150 - utime.ticks_diff(utime.ticks_ms(), tstart)
	if delta > 0:
		utime.sleep_ms(delta)

I raised the recursion limit by one and got the similar exception. After rising it to 5000 (1000 is the default) I no longer view it. Maybe I require to do few digging in my code because I am making many temporary objects in each iteration of an event loop.

Figurred out an infinite recursion problem in an overridden _getattr_ in my code and after solving this I no longer view this exception. You may mark this bug as green or delete it.

Answer 3

When you run a recursive function in Python on a large input ( > 10^4), you might face a “maximum recursion depth exceeded error”. This is a common scenario for a program when someone tries to run a program with a more extensive input range. To avoid the error, you can call the setrecursionlimit() function from the sys module in Python. This particular function modifies the recursion limit in Python. Using this function, we can set your recursion limit 10**6 to avoid the error. Let’s see how it works:

import sys
sys.setrecursionlimit(10**6) 
def fact(n):
	if(n == 0):
		return 1
	return n * fact(n - 1)
if __name__ == '__main__':
	f = int(input('Enter the number: \n'))
	print(fact(f))

Boom! Now you’ve increased the limit, and the program can calculate the factorial up to 10**6 range number. I hope this example will help you to understand.