我想根据一列数据打上序号，上下相同数据打相同序号？

Question

我想根据一列数据打上序号，上下相同数据打相同序号，不同数据序号+1，写了好久写不出来，有没有人教一下。

想要这样的效果

Answer 1

这样？

import numpy as np
import pandas as pd

df = pd.DataFrame({
    'data': [11, 21, 24, 24, 24, 24, 25, 25, 26, 26, 26, 26, 23, 26, 26, 26, 26, 20, 26, 26, 26, 26],
    'nums': 0,
})

df['nums'] = np.cumsum(df['data'].diff() != 0)

print(df)

结果：

    data  nums
0     11     1
1     21     2
2     24     3
3     24     3
4     24     3
5     24     3
6     25     4
7     25     4
8     26     5
9     26     5
10    26     5
11    26     5
12    23     6
13    26     7
14    26     7
15    26     7
16    26     7
17    20     8
18    26     9
19    26     9
20    26     9
21    26     9

Answer 2

import pandas as pd
import random
random.seed(10)
df=pd.DataFrame(
    {
        "Time":pd.date_range("2022-9-1 15:25:55",periods=40,freq="s"),
        "postiveVol":[random.randint(20,23) for _ in range(40)]
        }
    )
sno=[]
temp=df.postiveVol.tolist()
for i,v in enumerate(temp):
    if i==0:
        sno.append(1)
    elif v==temp[i-1]:
        sno.append(sno[-1])
    else:
        sno.append(sno[-1]+1)
df["序号"]=sno
print(df)

Answer 3

def cacu():
    df1 = {"postiveVol":[1,3,3,23,32,34,34]}
    my_list = df1["postiveVol"]
    my_list.sort()
    
    if(len(my_list) <= 0):
        return
    pre = my_list[0]
    base = 1
    output = []
    for v in my_list:
        if(pre != v):
            base +=1
        output.append(base)
        pre = v

    print(list(zip(my_list,output)))

[(1, 1), (3, 2), (3, 2), (23, 3), (32, 4), (34, 5), (34, 5)]

def cacu():
    df1 = {"postiveVol":[1,3,3,23,32,34,34]}
    my_list = df1["postiveVol"]
    my_list.sort()
    
    swap = dict(Counter(my_list))
    #print(swap)
    
    output = []
    for v in swap:
        base = 1
        for in_v in range(1,swap[v]+1):
            #print(in_v)
            output.append(in_v)
    print(list(zip(my_list,output)))
    #print(output)
    
cacu()

[(1, 1), (3, 1), (3, 2), (23, 1), (32, 1), (34, 1), (34, 2)]