Python snippets

  • Read file with Chinese
import codecs
with codecs.open('areachn.json', 'r', 'utf-8') as fp:
    a = json.load(fp)
  • Filter list
test = range(-5, 5)
lessthanzero = list(filter(lambda x:x < 0, test))
  • Sort list of turple
sorted(result, key=lambda x: x[0], reverse=True)
  • Combine to list
a = [1, 2]
b = [3, 4]
c = a + b
  • Sort a dictionary
import operator
x = {1:2, 3:4, 4:3, 1:0}
sorted_x = operator(x.items(), key=operator.itemgetter(1))
Filter dict by value
   sorted_dict = {k: v for k, v in areadata.items() if v > 0}
  • Reduce
from functools import reduce
product = reduce((lambda x, y: x+y), [1, 2, 3, 4])
  • Date time format code
Directive Description Example
%a Weekday, short version Wed
%A Weekday, full version Wednesday
%w Weekday as number, 0-6, 0 is Sunday 3
%d Day of month 01-31 31
%b Month name, short version Dec
%B Month name, full version December
%y Year, short version without century 22
%Y Year, full version 2022
%H Hour 00-23 17
%I Hour 00-12 05
%p AM/PM PM
%M Minute, 00-59 41
%S Second, 00-59 08
%f Microseconds, 000000-999999 548513
%z UTC offset +0100
%Z Timezone CST
%j Day number of year 000-366 365
%U Week number of year, Sunday as first day of week 52
%W Week number of year, Monday as first day of week 52
%c Local version of date and time Mon Dec 31 17:41:00 2022
%x Local version of date 12/31/22
%X Local version of time 17:41:00
%% A % character %