how to update an old dataframe from newest one

Question

i have this old DataFrame:

Énergie(keV)	Intensité(%)	Type	Parent	Période	Unité
13.31275	2.18	XL	Fr-221	4.79	min
78.94000	0.96	XKα2	Fr-221	4.79	min
81.51000	1.59	XKα1	Fr-221	4.79	min
92.30930	0.55	XKβ1	Fr-221	4.79	min

i want update the 3 first columns with;

Énergie(keV)	Intensité(%)	Type	Parent
13.31275	18	γ	Fr-221
75.94000	25	γ	Fr-221
89.51000	1.09	XKα1	Fr-221
99.00000	0.85	γ	Fr-221

I have a big dataframe , but they havn't a same dimensions;

I think something like ```old_df[['col1','col2','col3']] = new_df[['col1','col2','col3']]``` — Kabilan Mohanraj, Jun 20 '21 at 18:04
Hi. Is this what you're looking for? [https://stackoverflow.com/questions/24768657/replace-column-values-based-on-another-dataframe-python-pandas-better-way](https://stackoverflow.com/questions/24768657/replace-column-values-based-on-another-dataframe-python-pandas-better-way) — Kabilan Mohanraj, Jun 21 '21 at 05:39

score 0 · Answer 1 · answered Jun 20 '21 at 20:08

it look like this the old one:
|Énergie(keV)| Intensité(%)| Type | Parent | Période| Unité| |:-----------|:------------:|:-------:|:------:|:---------:|:-------:| |0.381 |0.019 |XL |Sc-44 |3.97 |h | |10.408 |0.45 |XL |Ti-44 |60.0 |a | |0.430 |0.00013 |XL |Fr-221 |83.788 |d |

the forth row mus be updated from the new dataframe

how to update an old dataframe from newest one

1 Answers1