1.1 Python的适用性

因本专集集中在Python在工业领域的应用，所以抛开在其他行业的应用不谈。本专集当中仅涉及官方版本的Python，其他发行版本在我有所了解后才会写东西介绍。

• 可以使用pyserial和串口RS232芯片通信 (TTL 3.3v之类的也类似，只是芯片不同)

import serial
# Open port at “9600,8,N,1”, no timeout
ser = serial.Serial('/dev/ttyUSB0')  # open Linux serial port
print(ser.name)         # check which port was really used
ser.write(b'hello')     # write a string
ser.close()             # close port

• 可以使用minimalmodbus和RS485芯片通信

#!/usr/bin/env python3
import minimalmodbus

instrument = minimalmodbus.Instrument('/dev/ttyUSB1', 1)  # port name, slave address (in decimal)

## Read temperature (PV = ProcessValue) ##
temperature = instrument.read_register(289, 1)  # Registernumber, number of decimals
print(temperature)

## Change temperature setpoint (SP) ##
NEW_TEMPERATURE = 95
instrument.write_register(24, NEW_TEMPERATURE, 1)  # Registernumber, value, number of decimals for storage

• 可以读写csv文件

import csv
with open('eggs.csv', newline='') as csvfile:
    spamreader = csv.reader(csvfile, delimiter=' ', quotechar='|')
    for row in spamreader:
        print(', '.join(row))
# output
>>> Spam, Spam, Spam, Spam, Spam, Baked Beans
>>> Spam, Lovely Spam, Wonderful Spam

• 可以操作数据库PyMySQL

import pymysql.cursors

# Connect to the database
connection = pymysql.connect(host='localhost',
                             user='user',
                             password='passwd',
                             db='db',
                             charset='utf8mb4',
                             cursorclass=pymysql.cursors.DictCursor)

try:
    with connection.cursor() as cursor:
        # Create a new record
        sql = "INSERT INTO `users` (`email`, `password`) VALUES (%s, %s)"
        cursor.execute(sql, ('webmaster@python.org', 'very-secret'))

    # connection is not autocommit by default. So you must commit to save
    # your changes.
    connection.commit()

    with connection.cursor() as cursor:
        # Read a single record
        sql = "SELECT `id`, `password` FROM `users` WHERE `email`=%s"
        cursor.execute(sql, ('webmaster@python.org',))
        result = cursor.fetchone()
        print(result)
finally:
    connection.close()

总结：所有基本的需求都可以直接或者外挂一些商用器件来实现

对于动不动就成千上万的NI LabVIEW软件和板卡来说成本低到吓人。