how to iterate for loop in efficient way?

Question



for index, i in df.iterrows():
    temp=df.loc[df['security_code']==df['security_code'][index]]

this loop is to map dataframe which has same security code it results in data of similar security code with different dates

above for loop iterates each row in dataframe and dataframe consist of 27,000 rows which takes hours to iterate all the rows

problem is iteration through dataframe which contains huge number of rows takes lot of time and will this loop result in infinte loop?

please read [how-to-make-good-reproducible-pandas-examples](https://stackoverflow.com/questions/20109391/how-to-make-good-reproducible-pandas-examples) — Brown Bear, Jun 20 '20 at 09:32
After you read it, please include a sample input and the expected output. — Roy2012, Jun 20 '20 at 10:36

Hugolmn · Answer 1 · 2020-06-20T17:25:40.987

0

IIUC there is no need to use for loop to get rows with index matching 'security_code' column:

temp = df[df['security_code'] == df.index]

Your current code will actually overwrite temp as many time as there are indexes in your DataFrame.

edited Jun 20 '20 at 17:25

answered Jun 20 '20 at 13:22

Hugolmn

ValueError: Lengths must match to compare – i_m_brunda Jun 20 '20 at 14:19
i get value error as two csv files are different sizes – i_m_brunda Jun 20 '20 at 14:20
I edited my answer. You want to get the dataframe having equal index and security_code right ? – Hugolmn Jun 20 '20 at 14:31
yes, i had to map security_code of different dates in same csv – i_m_brunda Jun 20 '20 at 17:22
Could you explain with more details what is the result you want to achieve ? – Hugolmn Jun 20 '20 at 17:27
i want to loop 20,000 rows within minimum possible time – i_m_brunda Jun 21 '20 at 15:40
But for WHAT result ? Please make a sentence explaining what your code was supposed to do. – Hugolmn Jun 21 '20 at 16:03

1 Answers1