python - 创建唯一的Id，读取多个文件时枚举不同的行值

Question

我想根据游戏名称和年份为此创建一个唯一的 ID。主要关注点是 col 名称。

我有多个文件:

Name   Year    Level   
Pikachu   2007    30
Pikachu   2007    20
Raichu    2007    20
Mew       2007    35

<小时/>

Name   Year    Level   
Pikachu   2008    50
Pikachu   2008    40
Raichu    2008    55
Mew       2008    55

<小时/> <小时/>

Pokemon   Year    Level   
Squirtle  2008    50
Pidgey    2008    40
Pidgey    2008    55
Ekans     2008    55

<小时/>

这是我想要的结果:

  Game     Name   Year    Level    Id 
Pokemon   Pikachu   2007    30     1
Pokemon   Pikachu   2007    20     1 
Pokemon   Raichu    2007    20     2
Pokemon    Mew      2007    35     3
Pokemon   Pikachu   2008    50     1
Pokemon   Pikachu   2008    40     1
Pokemon   Raichu    2008    55     2
Pokemon   Mewtwo    2008    55     3
Pokemon   Squirtle  2008    60     1
Pokemon    Pidgey   2008    45     2
Pokemon    Pidgey   2008    52     2
Pokemon    Ekans    2008    51     3

我尝试过这个:

for file in files:
   df = pd.read_csv(file,header=0)
   df['Game'] = 'Pokemon'
   for i, p in enumerate(df['Pokemon'].unique(), 1):
       df.loc[i-1,'id'] = i
       df.loc[i-1, 'Pokemon'] = p
   df['Id'] = df['Id'].astype('int')

Answer 1

我想你想要factorize每个DataFrame，对于最终的大DataFrame创建列表并最后通过 concat 连接在一起:

out = []
for file in files:
    df = pd.read_csv(file,header=0)
    df['Game'] = 'Pokemon'
    df['id'] = pd.factorize(df['Name'])[0] + 1
    out.append(df)

df = pd.concat(out, ignore_index=True)
print (df)
        Name  Year  Level     Game  id
0    Pikachu  2007     30  Pokemon   1
1    Pikachu  2007     20  Pokemon   1
2     Raichu  2007     20  Pokemon   2
3        Mew  2007     35  Pokemon   3
4    Pikachu  2008     50  Pokemon   1
5    Pikachu  2008     40  Pokemon   1
6     Raichu  2008     55  Pokemon   2
7        Mew  2008     55  Pokemon   3
8   Squirtle  2008     50  Pokemon   1
9     Pidgey  2008     40  Pokemon   2
10    Pidgey  2008     55  Pokemon   2
11     Ekans  2008     55  Pokemon   3