總和與GROUPBY不爲我用熊貓

Question

工作，我有以下數據集：

我想​​（名）用熊貓來總結列cantidad（金額）分組，所以我曾嘗試：

第一行是由於驚訝的 「安娜」 是一個共同的名字，所以我檢查：

好吧，那麼...「Ana」的總數是434而不是1.發生了什麼？我究竟做錯了什麼？

Answer 1

你需要skipinitialspace=True因爲​​列中的值有尾隨空格 - 所以'Ana'，' Ana'，' Ana ' ...被單獨分組：

historical_names = pd.read_csv('nombres-1920-1924.csv', skipinitialspace =True) 
print (historical_names.head()) 

resume = historical_names.groupby('nombre')['cantidad'].sum() 
print (resume['Ana']) 
437 

a = historical_names.loc[historical_names['nombre'] == 'Ana', 'cantidad'] 
print (a) 
5  113 
10340 138 
18776  1 
23114 183 
26523  2 
Name: cantidad, dtype: int64 

a = historical_names.loc[historical_names['nombre'] == 'Ana', 'cantidad'].sum() 
print (a) 
437 

---

historical_names = pd.read_csv('nombres-1920-1924.csv') 
print (historical_names.head()) 

historical_names['nombre'] = historical_names['nombre'].str.strip() 
resume = historical_names.groupby('nombre')['cantidad'].sum() 
print (resume['Ana']) 
437 

---

historical_names = pd.read_csv('nombres-1920-1924.csv') 
print (historical_names.head()) 

resume = historical_names.groupby('nombre')['cantidad'].sum() 
print (resume['Ana']) 
434 

a = historical_names.loc[historical_names['nombre'] == 'Ana', 'cantidad'] 
print (a) 
5  113 
10340 138 
23114 183 
Name: cantidad, dtype: int64 

a = historical_names.loc[historical_names['nombre'] == 'Ana', 'cantidad'].sum() 
print (a) 
434