Exceptions information

Exceptions information#

By adding the exc_info=True argument to the logging method, you can include information about the exception in the log.

import os
import logging

Basic example#

Here I create loggin system which will write any error to logging_files/basic.log

log_filename = "exception_information_files/basic.log"
fun_lines = [
    lambda: "no_bug", # no_bug function
    lambda: 7/0, # ZeroDivisionError
    lambda: "hello" + 5784 # TypeError
]

basic_logger = logging.getLogger("basic loger")
basic_logger.level = logging.INFO
handler = logging.FileHandler(log_filename, mode='w')
handler.setFormatter(
    logging.Formatter('%(asctime)s|%(levelname)s|%(message)s')
)
basic_logger.addHandler(handler)

for fun in fun_lines:
    try:
        fun()
    except:
        basic_logger.error("===Any error===", exc_info=True)

with open(log_filename) as file:
    print(file.read())
os.remove(log_filename)

2024-04-18 21:04:50,089|ERROR|===Any error===
Traceback (most recent call last):
  File "/tmp/ipykernel_8410/697886762.py", line 18, in <module>
    fun()
  File "/tmp/ipykernel_8410/697886762.py", line 4, in <lambda>
    lambda: 7/0, # ZeroDivisionError
ZeroDivisionError: division by zero
2024-04-18 21:04:50,089|ERROR|===Any error===
Traceback (most recent call last):
  File "/tmp/ipykernel_8410/697886762.py", line 18, in <module>
    fun()
  File "/tmp/ipykernel_8410/697886762.py", line 5, in <lambda>
    lambda: "hello" + 5784 # TypeError
TypeError: can only concatenate str (not "int") to str

Exception in exception#

I wanted to learn how looging module will process the situation when there is one exception is handled within the framework of the other. In the following example there are functions:

  • inside_exception calls the division by zero exception;

  • outside_exception will execute inside_exception and in addition will lead to type exception;

  • as a result we see only TypeError in log.

log_filename = "exception_information_files/excep_in_excep.log"
logging.basicConfig(
    level=logging.INFO, 
    filename=log_filename,
    filemode="w",
    format="%(asctime)s %(levelname)s %(message)s"
)

def inside_exception():
    try:
        7/0
    except:
        pass

def outside_exception():
    try:
        inside_exception()
        "hello" + 7
    except:
        logging.error("Any error", exc_info=True)

outside_exception()

with open(log_filename) as f:
    print(f.read())

2024-04-18 21:04:51,494 ERROR Any error
Traceback (most recent call last):
  File "/tmp/ipykernel_8410/1712082539.py", line 18, in outside_exception
    "hello" + 7
TypeError: can only concatenate str (not "int") to str
Contents