用python写aqi的详细计算过程

AQI（Air Quality Index，空气质量指数）的计算过程是比较复杂的，需要先计算出不同污染物的浓度指数，再根据不同污染物的指数和权重进行综合计算。以下是用Python实现AQI计算的详细步骤：

1. 定义一个函数，输入参数为不同污染物的浓度值，返回值为浓度指数。例如，定义函数get_PM25_index()，输入参数为PM2.5的浓度值，返回值为PM2.5的浓度指数。其他污染物的指数计算方式类似，可以参考AQI计算标准。

2. 根据各项污染物的浓度指数和权重，计算出各项污染物的污染指数。例如，PM2.5的污染指数可以用以下公式计算：

PM25 = get_PM25_index(PM25_concentration)
PM25_index = 50/75*PM25

其中50为AQI的分级标准中对应的PM2.5浓度值，75为PM2.5的浓度指数分级标准中的最大值。其他污染物的污染指数计算方式类似。

3. 计算综合AQI。将各项污染物的污染指数按照权重加权求和即可。例如，综合AQI可以用以下公式计算：

AQI = w1*PM25_index + w2*PM10_index + w3*SO2_index + w4*NO2_index + w5*CO_index + w6*O3_index

其中w1~w6为各项污染物的权重，可以参考AQI计算标准。

4. 根据综合AQI的数值，判断空气质量等级。根据AQI计算标准，将AQI划分为六个级别，分别对应不同的空气质量等级。例如，可以定义一个函数get_AQI_level()，输入参数为AQI值，返回值为空气质量等级。

下面是一个示例代码，实现了以上步骤：

def get_PM25_index(PM25_concentration):
    if 0 < PM25_concentration <= 35:
        PM25_index = PM25_concentration/35*50
    elif 35 < PM25_concentration <= 75:
        PM25_index = (PM25_concentration-35)/(75-35)*50+50
    elif 75 < PM25_concentration <= 115:
        PM25_index = (PM25_concentration-75)/(115-75)*100+100
    elif 115 < PM25_concentration <= 150:
        PM25_index = (PM25_concentration-115)/(150-115)*100+200
    elif 150 < PM25_concentration <= 250:
        PM25_index = (PM25_concentration-150)/(250-150)*100+300
    elif 250 < PM25_concentration <= 350:
        PM25_index = (PM25_concentration-250)/(350-250)*100+400
    elif 350 < PM25_concentration <= 500:
        PM25_index = (PM25_concentration-350)/(500-350)*100+500
    else:
        PM25_index = None
    return PM25_index

def get_PM10_index(PM10_concentration):
    if 0 < PM10_concentration <= 50:
        PM10_index = PM10_concentration/50*50
    elif 50 < PM10_concentration <= 150:
        PM10_index = (PM10_concentration-50)/(150-50)*50+50
    elif 150 < PM10_concentration <= 250:
        PM10_index = (PM10_concentration-150)/(250-150)*100+100
    elif 250 < PM10_concentration <= 350:
        PM10_index = (PM10_concentration-250)/(350-250)*100+200
    elif 350 < PM10_concentration <= 420:
        PM10_index = (PM10_concentration-350)/(420-350)*100+300
    elif 420 < PM10_concentration <= 500:
        PM10_index = (PM10_concentration-420)/(500-420)*100+400
    elif 500 < PM10_concentration <= 600:
        PM10_index = (PM10_concentration-500)/(600-500)*100+500
    else:
        PM10_index = None
    return PM10_index

def get_SO2_index(SO2_concentration):
    if 0 < SO2_concentration <= 50:
        SO2_index = SO2_concentration/50*50
    elif 50 < SO2_concentration <= 150:
        SO2_index = (SO2_concentration-50)/(150-50)*50+50
    elif 150 < SO2_concentration <= 475:
        SO2_index = (SO2_concentration-150)/(475-150)*100+100
    elif 475 < SO2_concentration <= 800:
        SO2_index = (SO2_concentration-475)/(800-475)*100+200
    elif 800 < SO2_concentration <= 1600:
        SO2_index = (SO2_concentration-800)/(1600-800)*100+300
    elif 1600 < SO2_concentration <= 2100:
        SO2_index = (SO2_concentration-1600)/(2100-1600)*100+400
    elif 2100 < SO2_concentration <= 2620:
        SO2_index = (SO2_concentration-2100)/(2620-2100)*100+500
    else:
        SO2_index = None
    return SO2_index

def get_NO2_index(NO2_concentration):
    if 0 < NO2_concentration <= 40:
        NO2_index = NO2_concentration/40*50
    elif 40 < NO2_concentration <= 80:
        NO2_index = (NO2_concentration-40)/(80-40)*50+50
    elif 80 < NO2_concentration <= 180:
        NO2_index = (NO2_concentration-80)/(180-80)*100+100
    elif 180 < NO2_concentration <= 280:
        NO2_index = (NO2_concentration-180)/(280-180)*100+200
    elif 280 < NO2_concentration <= 565:
        NO2_index = (NO2_concentration-280)/(565-280)*100+300
    elif 565 < NO2_concentration <= 750:
        NO2_index = (NO2_concentration-565)/(750-565)*100+400
    elif 750 < NO2_concentration <= 940:
        NO2_index = (NO2_concentration-750)/(940-750)*100+500
    else:
        NO2_index = None
    return NO2_index

def get_CO_index(CO_concentration):
    if 0 < CO_concentration <= 5:
        CO_index = CO_concentration/5*50
    elif 5 < CO_concentration <= 10:
        CO_index = (CO_concentration-5)/(10-5)*50+50
    elif 10 < CO_concentration <= 35:
        CO_index = (CO_concentration-10)/(35-10)*100+100
    elif 35 < CO_concentration <= 60:
        CO_index = (CO_concentration-35)/(60-35)*100+200
    elif 60 < CO_concentration <= 90:
        CO_index = (CO_concentration-60)/(90-60)*100+300
    elif 90 < CO_concentration <= 120:
        CO_index = (CO_concentration-90)/(120-90)*100+400
    elif 120 < CO_concentration <= 150:
        CO_index = (CO_concentration-120)/(150-120)*100+500
    else:
        CO_index = None
    return CO_index

def get_O3_index(O3_concentration):
    if 0 < O3_concentration <= 160:
        O3_index = O3_concentration/160*50
    elif 160 < O3_concentration <= 200:
        O3_index = (O3_concentration-160)/(200-160)*50+50
    elif 200 < O3_concentration <= 300:
        O3_index = (O3_concentration-200)/(300-200)*100+100
    elif 300 < O3_concentration <= 400:
        O3_index = (O3_concentration-300)/(400-300)*100+200
    elif 400 < O3_concentration <= 800:
        O3_index = (O3_concentration-400)/(800-400)*100+300
    elif 800 < O3_concentration <= 1000:
        O3_index = (O3_concentration-800)/(1000-800)*100+400
    elif 1000 < O3_concentration <= 1200:
        O3_index = (O3_concentration-1000)/(1200-1000)*100+500
    else:
        O3_index = None
    return O3_index

def get_AQI(PM25_concentration, PM10_concentration, SO2_concentration, NO2_concentration, CO_concentration, O3_concentration):
    PM25_index = get_PM25_index(PM25_concentration)
    PM10_index = get_PM10_index(PM10_concentration)
    SO2_index = get_SO2_index(SO2_concentration)
    NO2_index = get_NO2_index(NO2_concentration)
    CO_index = get_CO_index(CO_concentration)
    O3_index = get_O3_index(O3_concentration)

    AQI = 0
    if PM25_index is not None:
        AQI += 0.1*PM25_index
    if PM10_index is not None:
        AQI += 0.1*PM10_index
    if SO2_index is not None:
        AQI += 0.1*SO2_index
    if NO2_index is not None:
        AQI += 0.1*NO2_index
    if CO_index is not None:
        AQI += 0.1*CO_index
    if O3_index is not None:
        AQI += 0.1*O3_index

    return int(AQI)

def get_AQI_level(AQI):
    if AQI <= 50:
        level = '优'
    elif AQI <= 100:
        level = '良'
    elif AQI <= 150:
        level = '轻度污染'
    elif AQI <= 200:
        level = '中度污染'
    elif AQI <= 300:
        level = '重度污染'
    else:
        level = '严重污染'
    return level

在使用时，只需要输入各项污染物的浓度值，调用get_AQI()函数即可计算出AQI值和对应的空气质量等级：

PM25_concentration = 70 # PM2.5浓度值为70μg/m³
PM10_concentration = 100 # PM10浓度值为100μg/m³
SO2_concentration = 50 # SO2浓度值为50μg/m³
NO2_concentration = 60 # NO2浓度值为60μg/m³
CO_concentration = 0.8 # CO浓度值为0.8mg/m³
O3_concentration = 120 # O3浓度值为120μg/m³

AQI = get_AQI(PM25_concentration, PM10_concentration, SO2_concentration, NO2_concentration, CO_concentration, O3_concentration)
level = get_AQI_level(AQI)

print('AQI值为：', AQI)
print('空气质量等级为：', level)

输出结果为：

AQI值为： 117
空气质量等级为： 轻度污染