log analysis of nginx access using Python Pandas

My first step is to review logins on the site,
https://physicsderivationgraph.blogspot.com/2020/05/inspecting-list-of-users-who-have.html

My previous post on reviewing logs
https://physicsderivationgraph.blogspot.com/2020/05/grepping-nginx-logs-to-observe-user.html
was written prior to the current nginx format I'm using.

I haven't gotten around to a deeper analysis like
https://physicsderivationgraph.blogspot.com/2020/04/analysis-of-web-logs-to-understand-how.html

First I had to install supporting software

  sudo apt install python3-pip
  pip3 install pandas

Inline Python in bash with Pandas is possible because every line is formatted like a Python dictionary. Here I want to review what columns are present in the logs

cat nginx_access.log | python3 -c "import sys
import pandas
pandas.options.display.max_rows = 999 # https://pandas.pydata.org/pandas-docs/stable/user_guide/options.html
list_of_lines = []
for line in sys.stdin:
    list_of_lines.append(eval(line))
df = pandas.DataFrame(list_of_lines)
print(df.columns)
"

How many of each entry for a few columns?

cat nginx_access.log | python3 -c "import sys
import pandas
pandas.options.display.max_rows = 999 # https://pandas.pydata.org/pandas-docs/stable/user_guide/options.html
list_of_lines = []
for line in sys.stdin:
    list_of_lines.append(eval(line))
df = pandas.DataFrame(list_of_lines)
threshold = 20
print('user:')
vc = df['user'].value_counts()
print(vc[vc>threshold])
print('IP:')
vc = df['ip'].value_counts()
print(vc[vc>threshold])
print('req:')
vc = df['req'].value_counts()
print(vc[vc>threshold])
#print(df.head())
"

For IPs that have made multiple (e.g., 30) requests, what pages have been accessed?

cat nginx_access.log | python3 -c "import sys
import pandas
pandas.options.display.max_rows = 999 # https://pandas.pydata.org/pandas-docs/stable/user_guide/options.html
list_of_lines = []
for line in sys.stdin:
    list_of_lines.append(eval(line))
df = pandas.DataFrame(list_of_lines)
threshold = 30
vc = df['ip'].value_counts()
for ip, number_of_requests in vc[vc>threshold].items():
    print('\nIP = ',ip, 'made',number_of_requests,'requests')
    df_this_ip = df[df['ip']==ip]
    #for request in df_this_ip['req'].values:
    #    print(request)
    print(df_this_ip['req'].value_counts())
"