63 - 选择数据 - df[][] - df[选择指定列][筛选条件]

作用：有筛选条件

筛选df

import numpy as np
import pandas as pd
## roles = ['R1', 'R2', 'R3', 'R4']  # 要显示的列，可以自定义
roles = list(df)  # 要显示的列，list()此方法可以获得df的全部列
data = df[roles][
    (df['R0'] == "目标字符" )
    & (df['R0'] != "不要的目标字符" )
    & (df['R1'] < 20)
    & (df['R2'] > 20)
    & (df['R3'] < 1000)
    & (df['R4'] > 4000)
    & (df['R5'].isnull())  # 空的
    & (df["R6"].isin (["2","1"]))  # 在列表
    & (~ df["R7"].isin (["2","1"]))  # 不在列表
    &(df["R8"].str.contains("包含"))  # 包含
    ]
print (data)

## 注意，这里筛选之后，index是不变的，要改变index的话就要reset_index()

时间筛选

# hour = datetime.time(now.hour, now.minute, now.second, 0)
hour = datetime.time(12, 60, 60, 0)
role = list(df)
df = df[role][
    (df['start_time'] < hour)
    & (df['end_time'] > hour)
    ]

时间筛选

看本文章：选择数据 - df.loc[:,:] - 行名,列名 - 时间范围