Python counts csv data, calculates the number of repeated data, and deletes duplicate values

import os

import numpy as np

import pandas as pd

import time

start=() #Used to record program running time

('G:\\GISworkspace\\Rprocess')

tx=open('level3_river_clipV6.csv')

df=pd.read_csv(tx)

()

Cname=df['NAME_CH']

num=(range(0,len(Cname))) #Use to record the number of recurring occurrences of each place name

space=range(0,len(Cname))

space=(space,columns=['name'])

for i in range(len(Cname)):

k = 0 #Number of records

for j in range(len(Cname)):

if (Cname[i]==Cname[j]):

space['name'][i]=Cname[j]

k=k+1

else:

k=k

num[i] = k

num=(data=num,columns=['num'])

frame=[space,num] #concat performs two dataframe merging

result=(frame,axis=1) #axis=1 is a right connection, =0 is a down connection

result=result.drop_duplicates('name',keep='first') #Remove duplicate rows, you can use single columns or multiple columns, that is, result.drop_duplicates(['col1','col2'], keep='first'),

# keep='first' means only the value that appears first

result.to_csv('Cname_10km.csv') #Output

end=()

print(end-start) #Check program running time R runs 4.7min, python runs 31s