python - 使用 [key :value] combination in Python 将多列合并为一个列列表

Question

让我通过注意组合列不是字典来作为这个问题的序言。生成的数据框在“组合”列中有方括号 - 因此它看起来像数据框内的列表，格式为 [key1:value1, key2:value2, etc]。

我正在尝试从中转换我的数据框:

import pandas as pd
test = pd.DataFrame({'apples':['red','green','yellow'], 'quantity':
[1,2,3],'tasteFactor':['yum','yum','yuck']})

   apples  quantity tasteFactor
0     red         1         yum
1   green         2         yum
2  yellow         3        yuck

对于这种格式，将每行中的键和值组合到一个新列中:

   apples  quantity tasteFactor  combined
0     red         1         yum  ['apples':'red','quantity':'1','tastefactor':'yum']
1   green         2         yum  ['apples':'green','quantity':'2','tastefactor':'yum']
2  yellow         3        yuck  ['apples':'yellow','quantity':'3','tastefactor':'yuck']

试图将数据帧转换为每行的字典，但无法将其转换为列表。

test['combined'] = test.to_dict(orient='records')

生成的新列不需要是实际的列表类型。它可以是一个字符串。

以前在这里问过这个问题，但想澄清这个问题标题中的问题。 How to Create a List from a Dictionary within a DataFrame in Python

找到了以下密切相关的问题并尝试了它们的推导，这让我完成了一半但似乎无法获得完全正确的格式。

• Combine columns in a Pandas DataFrame to a column of lists in a DataFrame
• Merge multiple column values into one column in python pandas
• Convert Dataframe to a Dictionary with List Values
• How to create a dictionary of key : column_name and value : unique values in column in python from a dataframe

Answer 1

你可以使用 pandas dataframes 的 apply 方法来完成

import pandas as pd
df = pd.DataFrame({'apples':['red','green','yellow'], 'quantity':
[1,2,3],'tasteFactor':['yum','yum','yuck']})

col_names = df.columns

def func(row):
    global col_names
    list_ = [str(b)+':'+str(a) for a,b in zip(row,col_names.values.tolist())]
    return list_

x = list(map(func, df.values.tolist()))
df.loc[:,'combined'] = pd.Series(x)
# df
#    apples  quantity tasteFactor                                       combined
# 0     red         1         yum      [apples:red, quantity:1, tasteFactor:yum]
# 1   green         2         yum    [apples:green, quantity:2, tasteFactor:yum]
# 2  yellow         3        yuck  [apples:yellow, quantity:3, tasteFactor:yuck]