如何在Python中替換數據框中的子字符串

Question

我有一個數據框，我想根據另一個數據框在其中替換一些單詞：

import pandas as pd
dist = pd.DataFrame([["21","apple"],["25","balana"],["30","lemon"]],columns=["idx","item"])
a = pd.DataFrame(["apple - banana"],columns=["pf"])
a['pf'] = a['pf'].replace(dist["item"], dist["idx"], regex=True)
print(a)

我怎樣才能做到這一點？ （這不適用於當前形式）

Answer 1

您可以嘗試以下方法：

dist = pd.DataFrame([["21","apple"],["25","balana"],["30","lemon"]],columns= ["idx","item"])
a = pd.DataFrame(["apple - banana"],columns=["pf"])
b = dict(zip(dist["idx"], dist["item"]))

def replace_items(token):
    for key, value in b.items():
        token = token.replace(value, key)
    return token

a["pf"] = a["pf"].apply(replace_items)

請注意， dist數據balana的banana是balana 。 不知道這是否有意...

Answer 2

將翻譯表轉換為字典似乎可以解決問題：

import pandas as pd
dist = pd.DataFrame([["apple","21"],["banana","25"],["lemon","30"]],columns=["item","idx"])
dist = dist.set_index('item')['idx'].to_dict()
a = pd.DataFrame(["apple - banana"],columns=["pf"])
a['pf'] = a['pf'].replace(dist, regex=True)
print(a)