I'm been stuck on this one for a while. I'm trying to open a csv, sort by severity (Critical, High, Medium, Low) then overwrite the existing file. I'd also like to ignore the first wrote or add a header row. 

**Original CSV**

```
IP Address  Severity    Score
10.0.0.1    High        2302
172.65.0.1  Low         310
192.168.0.1 Critical    5402
127.0.0.1   Medium      1672`

```

**Modified/Sorted CSV**

```
IP Address  Severity    Score
192.168.0.1 Critical    5402
10.0.0.1    High        2302
127.0.0.1   Medium      1672 
172.65.0.1  Low         310

```

**Code**

```
import csv
crit_sev = "Critical"
high_sev = "High"
med_sev = "Medium"
low_sev = "Low"
reader = csv.reader(open('sample.csv', 'r'))
row=0
my_list = []
for row in reader:
    if row[1] == crit_sev:
        my_list.append(row)
    elif row[1] == high_sev:
        my_list.append(row)
    elif row[1] == med_sev:
        my_list.append(row)
    elif row[1] == low_sev:
        my_list.append(row)

writer = csv.writer(open("sample.csv", 'w'))
header = ['IP Address', 'Severity', 'Score']
writer.writerow([header])
for word in my_list:
    writer.writerow([word])

```

Any help would be appreciated.