Python: pandas.DataFrame 如何合併? 如何以keys參數建立雙層column name ; pd.concat(dfs, axis=1, keys = dic_name_df.keys() ) ;雙層column name的DF與Series或單層column name的DF做橫向(axis=1)合併會如何? 雙層column name被壓縮成單層的tuple

by 儲蓄保險王 · 2023-06-14

pandas官網說明:
keys : sequence, default None
If multiple levels passed, should contain tuples.
Construct hierarchical(分層的) index using the passed keys as the outermost level.

code:

import pandas as pd
from typing import Dict
dic_name_df:Dict[str,pd.DataFrame] = {
    'UFA125A': pd.DataFrame({
        'Length_1': [3.103559, 3.136321, 3.168799, ...],
        'Length_2': [2.84988, 2.84988, 2.84988, ...],
        'Length_3': [4.8768, 4.8768, 4.8768, ...],
        'Length_4': [0.27661, 0.279529, 0.282424, ...]
    }),
    'UED240E': pd.DataFrame({
        'Length_1': [2.046695, 2.070632, 2.094404, ...],
        'Length_2': [2.74828, 2.74828, 2.74828, ...],
        'Length_3': [4.8768, 4.8768, 4.8768, ...],
        'Length_4': [0.182415, 0.184548, 0.186667, ...]
    })
}

dfs = list(dic_name_df.values()) #長度2 #List[pd.DataFrame]
df_combined = pd.concat(dfs, axis=1, keys=dic_name_df.keys())
#dic_name_df.keys()長度也是2
pd.set_option("display.max_columns",None)
print(df_combined)