How to filter excel data by row? 
How to filter excel data by row? Say my data is 

```
for f in glob.glob('/Users/seb/PycharmProjects/data-transform/data/[I..O]*.xlsx'):
    df = pd.read_excel(f)
    all_data = all_data.append(df, ignore_index=True)

print(all_data.describe())
print(all_data.head())
```

But not sure how to filter for rows with certain string, so that input:

```
Date	Time	Variable	 value    
08/01/2017	06:00:05	 Occupancy_T4CHK_zoneA_1_Live          	83
08/01/2017	06:00:05	 Occupancy_T4CHK_totalConcourse_1_Live 	510
08/01/2017	06:00:05	 ProjQueueTime_T4CHK_zoneA_1_Live      	919.048
08/01/2017	06:00:05	 Flow_T4CHK_zoneA_1_Live               	0
08/01/2017	06:00:05	 ExpQueueTime_T4CHK_zoneA_1_Live       	357.688
08/01/2017	06:00:05	 Flow_T4CHK_zoneB_1_Live               	0
08/01/2017	06:00:05	 ProjQueueTime_T4CHK_zoneC_1_Live      	114.911
08/01/2017	06:00:05	 Flow_T4CHK_zoneC_1_Live               	0
08/01/2017	06:00:05	 ExpQueueTime_T4CHK_zoneC_1_Live       	355.909
08/01/2017	06:00:05	 Flow_T4CHK_zoneD_1_Live               	0
08/01/2017	06:00:05	 Flow_T4CHK_zoneE_1_Live               	0
08/01/2017	06:00:05	 Flow_T4CHK_zoneF_1_Live               	0
08/01/2017	06:00:05	 Flow_T4CHK_zoneG_1_Live               	0
08/01/2017	06:00:05	 Flow_T4CHK_zoneH_1_Live               	0
```

produces output is

```
08/01/2017	06:00:05	 Flow_T4CHK_zoneD_1_Live               	0
08/01/2017	06:00:05	 Flow_T4CHK_zoneE_1_Live               	0
08/01/2017	06:00:05	 Flow_T4CHK_zoneF_1_Live               	0
08/01/2017	06:00:05	 Flow_T4CHK_zoneG_1_Live               	0
08/01/2017	06:00:05	 Flow_T4CHK_zoneH_1_Live               	0
08/01/2017	06:00:10	 Flow_T4CHK_zoneD_1_Live               	0
08/01/2017	06:00:10	 Flow_T4CHK_zoneE_1_Live               	0
08/01/2017	06:00:10	 Flow_T4CHK_zoneF_1_Live               	0
08/01/2017	06:00:10	 Flow_T4CHK_zoneG_1_Live               	0
08/01/2017	06:00:10	 Flow_T4CHK_zoneH_1_Live               	0
```

 
 
