How to sort a list with user defined condition in python? -

i new python.i want sort list condition. ex:

i getting environment details , storing them list below. ls = ['qa','uat','prod','dev'] can order. ls = ['uat','qa','dev','prod']

but result list should be:

rls = ['prod','qa','uat','dev'] 

you use custom comparator function, described in https://wiki.python.org/moin/howto/sorting#the_old_way_using_the_cmp_parameter.

or can use key function (by passing key keyword argument list.sort) transform value being sorted different one:

>>> ls = ['qa','uat','prod','dev'] >>> ls.sort(key=lambda x: (1,x) if x=='dev' else (0,x)) >>> ls ['prod', 'qa', 'uat', 'dev'] >>> 

or same thing function:

>>> def my_key_func(x): ...     if x=='dev': ...         return (1,x) ...     else: ...         return (0,x) ... >>> ls.sort(key=my_key_func) >>> ls ['prod', 'qa', 'uat', 'dev'] >>>