How to check df coumn value befor load df

Using Streamlit
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1

boss
I am experiencing an error with my code when I attempt to assign the value of df[column] to a variable and subsequently check it using an if condition. I would appreciate it if you could review my code and provide the correct version. Thank you in advance for your assistance.
this is my code
import pandas as pd
import streamlit as st

if ‘df_base’ not in st.session_state:
st.session_state.df_base = pd.DataFrame({‘a’: [1, 2, 3],‘aa’: [4, 5, 6], ‘b’: [11, 22, 33], ‘c’: [‘x’, ‘y’, ‘z’]})
df = st.session_state.df_base
st.markdown(‘Column “b” is editable, and will affect column “d” = “a” + “b”’)
c1, c2, c3, c4 = st.columns(4, gap=“small”)
with c4:
df_right = df[[‘aa’]]
val1 = df[‘a’]
if val1>1:
df_right[‘aa’] = df[‘a’] + df[‘a’]
st.dataframe(df_right)

st.markdown(‘TODO:\n’
‘* hide the indices of the edit & right dfs\n’
‘* “squeeze” the dfs together’)

2

val1 > 1 cannot be converted to a bolean value. The correct version depends on your intent.

3

I am new to Streamlit and would appreciate guidance on how to retrieve column values for conditional checks, which will be used for further processing of another DataFrame column.

4

It is not a streamlit issue, it is a pandas syntax.
df['a'] is a column, when you compare it to a scalar like df['a'] > 1 it returns a boolean column with the results of each element in that column with this scalar.
so for your example, if df['a'] = [1,2,3], the results of df['a'] > 1 will be [False, True, True].

So your if-statement is unclear on what you want to do with those results.
you can use the any or all functions to convert the results into a single boolean value according to your desired logic.

5

thank you for your reply
I would like to verify the values in the CSV file’s column against the DataFrame. If the quantity exceeds 100, please apply a 10% discount in the subsequent column; otherwise, indicate 0 in the next column.

please guide me how i check the df column value

regard