python时间格式化字符串_python格式化日期字符串

主要用到两个库，time和datetime

import time

import datetime

import re

# 格式化日期字符串

def formatDateStr(date_string, target_pattern='%Y-%m-%d'):

# 日期格式转换(yyyy-MM-dd HH:mm:ss,yyyy/MM/dd,yyyyMMdd

patterns = {'%Y-%m-%d %H:%M:%S': '\d{4}-[01]\d-[0123]\d\s{1,2}[012]\d:[0-5]\d:[0-5]\d',

'%Y/%m/%d': '\d{4}/[01]\d/[0123]\d',

'%Y%m%d': '\d{4}[01]\d[0123]\d'}

for key, value in patterns.items():

if re.match(value, date_string, re.M | re.I):

# 字符转换为tuple

time_tuple = time.strptime(date_string, key)

# tuple转化为字符串

return time.strftime(target_pattern, time_tuple)

else:

pass

return ''

def formatDateStr2(date_string, target_pattern='%Y-%m-%d'):

# 日期格式转换(yyyy-MM-dd HH:mm:ss,yyyy/MM/dd,yyyyMMdd

patterns = {'%Y-%m-%d %H:%M:%S': '\d{4}-[01]\d-[0123]\d\s{1,2}[012]\d:[0-5]\d:[0-5]\d',

'%Y/%m/%d': '\d{4}/[01]\d/[0123]\d',

'%Y%m%d': '\d{4}[01]\d[0123]\d'}

for key, value in patterns.items():

if re.match(value, date_string, re.M | re.I):

# 字符转换为time

date = datetime.datetime.strptime(date_string, key)

# 获取年

year = datetime.datetime.strptime(date_string, key).year

# 获取月

month = datetime.datetime.strptime(date_string, key).month

# 获取日

day = datetime.datetime.strptime(date_string, key).day

return date.strftime(target_pattern)

else:

pass

return ''

def formatTimeStr(time_str, target_pattern='%H:%M:%S'):

patterns = {'%H:%M:%S': '[012]\d:[0-5]\d:[0-5]\d', '%H%M%S': '[012]\d[0-5]\d[0-5]\d'}

for key, value in patterns.items():

if re.match(value, time_str, re.M | re.I):

# 字符转换为tuple

time_tuple = time.strptime(time_str, key)

# tuple转化为字符串

return time.strftime(target_pattern, time_tuple)

else:

pass

return time_str

# 计算两个时间段的天数

def formatCycleTime(date_string):

# 日期格式转化2019.01.18-2019.03.15

patterns = {'%Y.%m.%d-%Y.%m.%d': '\d{4}\.[01]\d\.[0123]\d-\d{4}\.[01]\d\.[0123]\d',

'%Y/%m/%d-%Y/%m/%d': '\d{4}\/[01]\d\/[0123]\d-\d{4}\/[01]\d\/[0123]\d'}

for key, value in patterns.items():

if re.match(value, date_string, re.M | re.I):

dates = date_string.split('-')

startDate = dates[0]

endDate = dates[1]

d1 = datetime.datetime.strptime(startDate, key.split('-')[0])

d2 = datetime.datetime.strptime(endDate, key.split('-')[0])

return (d2 - d1).days

return ''

def parseTimeStamp2Date(timestamp):

# 时间戳转化为time

return time.localtime(timestamp)

def parseDate2TimeStamp(time_tuple):

# 转化为时间戳

return time.mktime(time_tuple)

if __name__ == '__main__':

str = '2019-08-29 23:59:49'

print(formatDateStr(str))

print(formatDateStr2(str))

运行结果：

时间字符串格式化