python - 将字符串追加到Pandas数据框中不会产生结果

Question

我有一个使用Pandas和交易数据的数据框，看起来像这样。

"Transactions",                 "State in transaction"
"Company name, Florida",         "N/A"
"Company name, California",      "N/A"
"Company name, Mississipi",      "N/A"
"Company name",                  "N/A"
             .                           .
             .                           .
             .                           .

依此类推...我也有一个包含美国和加拿大各州的数据框。看起来像这样:

"Alberta"
"British Columbia"
"Manitoba"
    .
    .
    .

如果状态在事务中，我该如何插入它，那么它应该给出这样的内容(如果在事务中未找到状态，则不适用):

"Transactions",                  "State in transaction"
"Company name, Florida",         "Florida"
"Company name, California",      "California"
"Company name, Mississipi",      "Mississipi"
"Company name",                  "N/A"
             .                           .
             .                           .
             .                           .

目前我已经尝试:

for i, transaction in enumerate(df["Transactions"]):
    for state in df_states:
        if state in transaction
            df["State in transaction"].append(state)
            break

任何帮助表示赞赏。
谢谢

Answer 1

您可以使用str.extract()。另外，我假设您的列名在下面的可复制代码中带有引号。列名称/值中的引号使它有点困惑。您的数据中是否包含实际报价？:

df = pd.DataFrame({'Transactions': {0: 'Company name, Florida',
  1: 'Company name, California',
  2: 'Company name, Mississipi',
  3: 'Company name'}})
df['State in transaction'] = df['Transactions'].str.extract(', (\w+)').fillna('N/A')
df

Out[1]: 
               Transactions State in transaction
0     Company name, Florida              Florida
1  Company name, California           California
2  Company name, Mississipi           Mississipi
3              Company name                  N/A