This is my participation 8 The fourth of the yuegengwen challenge 8 God , Check out the activity details ：8 Yuegengwen challenge Hello everyone , Today I'd like to introduce some good comments Python library , I hope it will be helpful to your project preparation .

Arrow

Python There are too many standard library modules and types , Time zone conversion trouble , and Arrow Is a more intelligent Python Time processing library . It implements and updates the date time type , Support the creation of 、 operation 、 Format and convert dates 、 Time and time stamp , You can use less import and code to process dates and times .

github.com/crsmithdev/…

install ：pip install arrow

import arrow
# Time in the local time zone 、 year 、 month 、 Japan 、 when
print(arrow.now())
print(arrow.now().year)
print(arrow.now().month)
print(arrow.now().day)
print(arrow.now().hour)
# Gets the time in the specified time zone
print(arrow.now('US/Pacific'))
# Get the timestamp
print(arrow.now().timestamp())
# Arrow Object to string time
print(arrow.now().format(fmt="YYYY-MM-DD HH:mm:ss"))
# Timestamp to date
timeStamp = 1625034427.024892
i = arrow.get(timeStamp)
print(i.format('YYYY-MM-DD HH:mm:ss'))
# One year before the current time ,1 Months ago ,2 Zhou Qian ,3 Days later ,2 Hours later
print(arrow.now().shift(years=-1, months=-1, weeks=-2, days=3, hours=2).format())
print(arrow.utcnow().span('hour'))
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jsonpath

jsonpath Used to resolve json data , It's a simple way to extract a given JSON Part of the document . It provides a regular expression like syntax , Can parse complex nested data structures , It is very convenient to extract the data information returned by the interface .

install ：pip install jsonpath

Use ：

from jsonpath import jsonpath
ret = jsonpath(dic, ' Syntax rule string ')
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jsonpath Rule of grammar

psutil

A cross platform method for monitoring hardware information Python library , Can monitor 、 Analyze the process of the operating system 、cpu、 Memory 、 The Internet 、 Use of disk and other resources .

psutil The functions implemented are similar to linux Many resource monitoring commands in , Such as ps、 top、 iotop、 lsof、 netstat、 ifconfig、 free etc. , Of course , You can combine Python Programming , To achieve more advanced functions , For example, combining with the front-end framework to realize visual resource monitoring resource information .

github.com/giampaolo/p…

install ：pip install psutil

see CPU

import psutil
# cpu The number of logics
print(psutil.cpu_count())
# every other 1 Output every... Seconds cpu The usage rate of
for x in range(3):
# interval： every other 0.5s Refresh once
# percpu： View all cpu Usage rate
print(psutil.cpu_percent(interval=1, percpu=True))
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Look at the memory

import psutil
# Output memory usage （ Total memory 、 Available memory 、 Memory usage 、 Used memory ）
print(psutil.virtual_memory())
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svmem(total=17126330368, available=8755355648, percent=48.9, used=8370974720, free=8755355648)
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disk IO

import psutil
# disk IO Information read_count( read IO Count ),write_count( Write IO Count )、read_bytes(IO Number of bytes written ),read_time( Disk read time ),write_time( Disk write time )
print(psutil.disk_io_counters())
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sdiskio(read_count=308820, write_count=193263, read_bytes=6779938304, write_bytes=3320958976, read_time=7298, write_time=2630)
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The Internet

import psutil
# bytes_sent: Number of bytes sent
# bytes_recv: Bytes received
# packets_sent: The amount of packet data sent
# packets_recv: The amount of packet data received
# errin: When receiving packets , Number of errors
# errout: When sending a packet , Number of errors
# dropin: When receiving packets , Number of discards
# dropout: When sending a packet , Number of discards
print(psutil.net_io_counters())
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snetio(bytes_sent=19362924, bytes_recv=159579883, packets_sent=118788, packets_recv=184342, errin=0, errout=0, dropin=0, dropout=0)
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github.com/jd/tenacity

tenacity

tenacity It's a Apache 2.0 Authorized universal retrial Library , Automated tests or crawlers , When the network instability causes the request to time out or wait for the conditions to be met , We can go through tenacity Implement the retry function of the code .

github.com/jd/tenacity

pip install tenacity
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Very simple to use , Directly add the decorator to use .

retry 3 Time

import tenacity
from tenacity import stop_after_attempt
@tenacity.retry(stop=stop_after_attempt(3))
def retry_test():
print(" retry ...")
raise Exception
retry_test()
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retry 10 second

import tenacity
from tenacity import stop_after_delay
@tenacity.retry(stop=stop_after_delay(10))
def retry_test():
print(" retry ...")
raise Exception
retry_test()
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every other 2 Seconds to retry

import tenacity from tenacity import wait_fixed

@tenacity.retry(wait=wait_fixed(2)) def wait_2_s(): print("Wait 2 second between retries") raise Exception

print(wait_2_s)