list
多层嵌套列表转换成单层
list =[1,[2,3,[4,5]]] convert to list = [1,2,3,4,5,6]
def flatten(nums):
res = []
for i in nums:uuts
if isinstance(i, list):
res.extend(flatten(i))
else:
res.append(i)
return res
# print(flatten(["junk",["nested stuff"],[],[[]]])) 比较两个list之间的差异
python比较两个list之间的差异、相同（差集、交集、并集）
https://blog.51cto.com/lj23for1/2139933?source=dra
listA = ['zhangsan', 'lisi', 'wangwu']
listB = ['zhangsan', 'lisi', 'zhaoliu']
# 1.差集
# listA对应listB的差集(A和B哪个不相同)
set(listA).difference(set(listB))
# set(['wangwu'])
# listB对应listA的差集(B和A哪个不相同)
set(listB).difference(set(listA))
# set(['zhaoliu'])
# 2.交集
set(listA).intersection(set(listB))
# set(['lisi', 'zhangsan'])
# 3.并集
set(listA).union(set(listB))
set(['lisi', 'zhaoliu', 'zhangsan', 'wangwu'])list根据多个条件进行排序
按照日期和场次进行升序排序
l = [['周四001','2019-12-26 23:00'],
['周四002','2019-12-26 23:00'],
['周四003','2019-12-26 20:00'],
['周四005','2019-12-26 21:00'],
['周四004','2019-12-26 21:00']]
nl = sorted(l,key = lambda x:(x[1],x[0]),reverse=False)
print(nl)list中的元素去重
# 方法一
data = [1,2,3,2,1,5,4,7]
data = list(set(data))
print(data)
# 方法二
data = [1,2,3,2,1,5,4,7]
new_data = []
for i in data:
if i not in new_data:
new_data.append(i)
print(new_data)删除列表中相邻的重复值
l = ['a', 'b', 'c', 'c','d','d' ,'e', 'e', 'e', 'f']
for i in range(len(l)-1,0,-1):
if l[i] == l[i-1]:
del l[i]
print(l)
# ['a', 'b', 'c', 'd', 'e', 'f']将列表中的元素顺序打乱
from random import shuffle
x = [1,2,3,4,5]
shuffle(x)
print(x)字符串
字符串去除空格
str = ' a b c '
# strip去除左右
print(str.strip())
# lstrip去除左
print(str.lstrip())
# rstrip去除右
print(str.rstrip())
# replace()去除所有
print(str.replace(' ',''))字符串替换多次
str = '[-1]'
# 去除左右括号
print(str.replace('[','').replace(']',''))取字符串某个字符前面或后面的值
# 取'-'两边的数值
str = '21-33'
print(str[0:str.index('-')])
print(str[str.index('-')+1:])
# 使用分割函数
a = '20.5.48'
b = a.split('.')
print(b)字母和数字的转换
# ord:字母to数字 chr:数字to字母
for i in range(ord('a'),ord('z')):
print (i,chr(i))time/date
获取某一天是星期几
参考网址：http://www.jb51.net/article/68962.htm
import time,datetime
date = '2019-12-24'
date = datetime.datetime.strptime(date,'%Y-%m-%d')
# day = date.weekday() # 使用该方法可以获取到星期对应的id
# print(day) # 0,1,2,3,4,5,6 => 一,二,三,四,五,六,日
def get_week_day(date):
week_day_dict = {
0 : '周一',
1 : '周二',
2 : '周三',
3 : '周四',
4 : '周五',
5 : '周六',
6 : '周日',
}
day = date.weekday()
return week_day_dict[day]
print(get_week_day(date))字符串和日期之间的转换
import datetime
date_str = '2019-12-12'
date = datetime.datetime.strptime(date_str,'%Y-%m-%d') # string to datetime.datetime
date_str = date.strftime("%Y-%m-%d") # date to string日期+1天
import datetime
n = 1
start_date_str = '2019-12-12'
start_date = datetime.datetime.strptime(start_date_str,'%Y-%m-%d')
delta = datetime.timedelta(days=int(n))
date = start_date +delta
print(date)将时间差换算成小时
import datetime
l = ['2017-01-02 23:00', '2017-01-03 12:20', '2017-01-08 22:00',
'2017-01-08 23:00','2017-01-14 03:00']
day1 = datetime.datetime.strptime(l[1],'%Y-%m-%d %H:%M')
day2 = datetime.datetime.strptime(l[0],'%Y-%m-%d %H:%M')
print(day1,day2)
a = day1 - day2
hour = ((a.days * 24 * 60 ) + a.seconds/60)/60
print(hour)
print(type(hour))Pandas
datetime格式化
# RangeIndex: 90 entries, 0 to 89
# Data columns (total 13 columns):
# id 90 non-null int64
# type_ 90 non-null object
# match_no_id 90 non-null int64
# datetime 90 non-null datetime64[ns]
df['new_datetime'] = df['datetime'].apply(lambda x : x.strftime('%Y-%m-%d %H'))
# datetime new_datetime
# 2020-01-19 00:00:00.000038 -> 2020-01-19 00
