xianhu · NingboYu-1990 · Nov 11, 2021
diff --git a/README.md b/README.md
@@ -66,6 +66,8 @@
 
 ### Plotly目录: 一些plotly画图的实例，使用jupyter notebook编写
 
+### python_arrow.py Python最好用的时间日期库 Arrow 的使用介绍
+
 ===================================================================================================
 
 ### 您可以fork该项目, 并在修改后提交Pull request, 看到后会尽量进行代码合并
diff --git a/python_arrow.py b/python_arrow.py
@@ -0,0 +1,171 @@
+# _*_ coding: utf-8 _*_
+
+"""
+Arrow ---- the best python time package I ever used, by Ningbo Yu.
+First you need get arrow package ready by: pip install arrow
+Doc reference: https://arrow.readthedocs.io/en/latest/
+"""
+
+# Let's begin with import
+import arrow
+from datetime import datetime
+
+now = arrow.now()  # Get current time with now
+print(now)  # Get an arrow object: 2021-11-10T10:41:46.963759+08:00
+utc_now = arrow.utcnow()  # Get UTC current time with now
+print(utc_now)  # Get an arrow object: 2021-11-10TT10:41:46.963759+00:00
+us_pacific_now = arrow.now('US/Pacific')  # Get current time of a specific time zone, pass a timezone to now()
+us_pacific_now_other_way = arrow.now('-07:00')  # Same as arrow.now('US/Pacific')
+
+
+########################################################
+# Create arrow object from string, datetime object, int
+########################################################
+date_str = '2021-10-10'
+arrow_obj_0 = arrow.get(date_str)
+print(arrow_obj_0)  # Get an arrow object: 2021-10-10T00:00:00+00:00
+arrow_obj_1 = arrow.get(date_str, tzinfo='US/Pacific')  # Specify time zone
+
+complex_date_str = 'June was born in May 1980'
+# For complex date string, you need to tell arrow how to parse by passing date format to get()
+# For date format reference see https://arrow.readthedocs.io/en/latest/ (Search 'Supported Tokens')
+arrow_obj_2 = arrow.get(complex_date_str, 'MMMM YYYY')
+# Create from a datetime object, if you are addicted to datetime package.
+datetime_obj = datetime.utcnow()
+arrow_obj_3 = arrow.get(datetime_obj)
+print(arrow_obj_3)  # Get an arrow object: 2021-11-10T03:40:35.912181+00:00
+# Create from a timestamp
+current_timestamp = 1636515897
+arrow_obj_4 = arrow.get(current_timestamp)
+
+
+#######################################################################
+# Powerful arrow functions, what makes arrow the best python time package
+#######################################################################
+arrow_obj = arrow.now()  # Output: <Arrow [2021-11-10T10:41:46.963759+08:00]>
+timestamp = arrow_obj.timestamp  # Get the timestamp from an arrow obj
+print(timestamp)  # Output: 1636512106
+# Convert arrow obj to datetime obj
+datetime_obj = arrow_obj.datetime
+# Output: datetime.datetime(2021, 11, 10, 10, 41, 46, 963759, tzinfo=tzoffset(None, 28800))
+
+# Shift forward or backward, much more easier to use than datetime package
+yesterday = arrow_obj.shift(days=-1)  # Output: <Arrow [2021-11-09T10:41:46.963759+08:00]>
+tomorrow = arrow_obj.shift(days=1)  # Output: <Arrow [2021-11-11T10:41:46.963759+08:00]>
+a_month_ago = arrow_obj.shift(months=-1)  # Output: <Arrow [2021-10-10T10:41:46.963759+08:00]>
+a_month_after = arrow_obj.shift(months=1)  # Output: <Arrow [2021-12-10T10:41:46.963759+08:00]>
+# Notes: a negative value means shift backward, a positive one is forward.
+# Besides days, months, you can also shift years/weeks/hours/minutes/seconds backward or forward.
+
+# Get general attributes from arrow object
+year = arrow_obj.year  # Output: 2021
+month = arrow_obj.month  # Output: 11
+week = arrow_obj.week  # Output: 45
+day = arrow_obj.day  # Output: 10
+hour = arrow_obj.hour  # Output: 10
+minute = arrow_obj.minute  # Output: 41
+second = arrow_obj.second  # Output: 46
+
+# Floor and ceil
+# Get the begin of the day
+day_begin = arrow_obj.floor('day')  # Output: <Arrow [2021-11-10T00:00:00+08:00]>
+day_end = arrow_obj.ceil('day')  # Output: <Arrow [2021-11-10T23:59:59.999999+08:00]>
+# You can get the very beginning of the year or month by:
+year_begin = arrow_obj.floor('year')
+month_begin = arrow_obj.floor('month')
+# and where the year and month ends:
+year_end = arrow_obj.ceil('year')
+month_end = arrow_obj.ceil('month')
+
+# Timezone conversation
+# If you want to get all timezones use the codes below:
+import pytz
+print(pytz.all_timezones)
+# Convert UTC to US/Pacific
+utc_time = arrow.utcnow()
+pacific_time = utc_time.to('US/Pacific')
+# Convert UTC to Asia/Shanghai
+shanghai_time = utc_time.to('Asia/Shanghai')
+# Convert UTC to local
+local_time = utc_time.to('local')
+
+# Replace
+# If you want to replace any part(year/month/day/hour/minute/second/tzinfo) with any other value, using replace:
+# Replace hour and day
+present = arrow.now()
+replace_d_h = present.replace(day=6, hour=6)
+# Replace month and second
+replace_m_s = present.replace(month=1, second=10)
+# Replace the timezone without changing other attributes
+replace_tz = present.replace(tzinfo='US/Pacific')
+
+# Convert arrow obj to string
+present.format('YYYY-MM-DD HH:mm:ss ZZ')  # Output: 2021-11-10 10:50:13 +08:00
+present.format('YYYY-MM-DD HH:mm:ss')  # Output: 2021-11-10 10:50:13
+present.format('YYYY-MM-DD')  # Output: 2021-11-10
+# Just pass the format to format function to get any format you want
+
+# Ranges & Spans
+print(arrow.now().span('hour'))
+# Output: (<Arrow [2021-11-11T10:00:00+08:00]>, <Arrow [2021-11-11T10:59:59.999999+08:00]>)
+print(arrow.now().span('day'))
+# Output: (<Arrow [2021-11-11T00:00:00+08:00]>, <Arrow [2021-11-11T23:59:59.999999+08:00]>)
+print(arrow.now().span('week'))
+# Output: (<Arrow [2021-11-08T00:00:00+08:00]>, <Arrow [2021-11-14T23:59:59.999999+08:00]>)
+print(arrow.now().span('month'))
+# Output: (<Arrow [2021-11-01T00:00:00+08:00]>, <Arrow [2021-11-30T23:59:59.999999+08:00]>)
+print(arrow.now().span('year'))
+# Output: (<Arrow [2021-01-01T00:00:00+08:00]>, <Arrow [2021-12-31T23:59:59.999999+08:00]>)
+
+# Using range to generate dates in a specific date range
+# To get dates between 2020-10-05 and 2020-10-12
+begin = arrow.get('2020-10-05')
+end = arrow.get('2020-10-12')
+day_range = arrow.Arrow.range('day', begin, end)
+print(list(day_range))
+"""
+Output: 
+[
+<Arrow [2020-10-05T00:00:00+00:00]>, <Arrow [2020-10-06T00:00:00+00:00]>, 
+<Arrow [2020-10-07T00:00:00+00:00]>, <Arrow [2020-10-08T00:00:00+00:00]>, <Arrow [2020-10-09T00:00:00+00:00]>, 
+<Arrow [2020-10-10T00:00:00+00:00]>, <Arrow [2020-10-11T00:00:00+00:00]>, <Arrow [2020-10-12T00:00:00+00:00]>
+]
+"""
+# You can get second/minute/hour/week/month/year range in the same way
+week_range = arrow.Arrow.range('week', begin, end)
+print(list(week_range))
+"""
+Output:
+[<Arrow [2020-10-05T00:00:00+00:00]>, <Arrow [2020-10-12T00:00:00+00:00]>]
+"""
+# Using span_range to generate span in a specific date range
+day_span = arrow.Arrow.span_range('day', begin, end)
+print(list(day_span))
+"""
+Output:
+[
+(<Arrow [2020-10-05T00:00:00+00:00]>, <Arrow [2020-10-05T23:59:59.999999+00:00]>),
+ (<Arrow [2020-10-06T00:00:00+00:00]>, <Arrow [2020-10-06T23:59:59.999999+00:00]>), 
+ (<Arrow [2020-10-07T00:00:00+00:00]>, <Arrow [2020-10-07T23:59:59.999999+00:00]>), 
+ (<Arrow [2020-10-08T00:00:00+00:00]>, <Arrow [2020-10-08T23:59:59.999999+00:00]>), 
+ (<Arrow [2020-10-09T00:00:00+00:00]>, <Arrow [2020-10-09T23:59:59.999999+00:00]>), 
+ (<Arrow [2020-10-10T00:00:00+00:00]>, <Arrow [2020-10-10T23:59:59.999999+00:00]>), 
+ (<Arrow [2020-10-11T00:00:00+00:00]>, <Arrow [2020-10-11T23:59:59.999999+00:00]>), 
+ (<Arrow [2020-10-12T00:00:00+00:00]>, <Arrow [2020-10-12T23:59:59.999999+00:00]>)
+]
+"""
+week_span = arrow.Arrow.span_range('week', begin, end)
+print(list(week_span))
+"""
+Output:
+[
+(<Arrow [2020-10-05T00:00:00+00:00]>, <Arrow [2020-10-11T23:59:59.999999+00:00]>), 
+(<Arrow [2020-10-12T00:00:00+00:00]>, <Arrow [2020-10-18T23:59:59.999999+00:00]>)
+]
+"""
+month_span = arrow.Arrow.span_range('month', begin, end)
+print(list(month_span))
+"""
+Output:
+[(<Arrow [2020-10-01T00:00:00+00:00]>, <Arrow [2020-10-31T23:59:59.999999+00:00]>)]
+"""