[python] How to round each item in a list of floats to 2 decimal places?

You can use the built-in map along with a lambda expression:

my_list = [0.2111111111, 0.5, 0.3777777777]
my_list_rounded = list(map(lambda x: round(x, ndigits=2), my_list))
my_list_rounded                                                                                                                                                                                                                 
Out[3]: [0.21, 0.5, 0.38]

Alternatively you could also create a named function for the rounding up to a specific digit using partial from the functools module for working with higher order functions:

from functools import partial

my_list = [0.2111111111, 0.5, 0.3777777777]
round_2digits = partial(round, ndigits=2)
my_list_rounded = list(map(round_2digits, my_list))
my_list_rounded                                                                                                                                                                                                                 
Out[6]: [0.21, 0.5, 0.38]