Generator comprehensions return generator in single assignment variable, but in multiple assignment it doesn’t return generators. # generator comprehension gen = ((x for x in [1, 2, 3])) gen >><generator object <genexpr> at 0x7f92b4e33500> # returns not generator but each…
Python: List Comprehensions are better
Using List Comprehensions, we don’t have to write ‘lamda’ expressions to map or filter values and the code is simpler. dct_lst = [{‘key1’: 1, ‘key2’: 2}, {‘key1’: 2, ‘key2’: 3}] # using list comprehension result = [x[‘key2’] * 10 for x…
Linux: Check process restarted
To check whether a process was restarted, look ‘/var/run/{process name}.pid’ file’s timestamp. # before % ll /var/run/apache2/apache2.pid -rw-r–r– 1 root root 5 March 22 11:10 /var/run/apache2/apache2.pid # restart % sudo service apache2 restart * Restarting web server apache2 # the…
Linux: grep \ or $
$ cat file aaa bbb\ccc bbb$ccc $ grep \\\\ file bbb\ccc $ grep ‘\\’ file bbb\ccc $ grep \\$ file bbb$ccc $ grep ‘\$’ file bbb$ccc