Why read_sas is converting strings to float? - python-3.x

Question

I am trying to read a .sas7bdat file using pandas and I am having a hard time because pandas is converting strings values that look like a number into float.
For example, if I have a telephone number like '348386789' and I read it with the following code:
import pandas as pd
df = pd.read_sas('test.sas7bdat', format='sas7bdat', encoding='utf-8')
The output would be 348386789.0!
I can convert every single column with something like df['number'].astype(int).astype(str) but this would be very unefficent.
There is the same problem in the read_csv function but there you can use the argument dtype that sets the type for the required column (es. dtype={'number': str)}).
Is there a better way to read values in the desired format and use it in a dataframe?
UPDATE
I even tried sas7bdat.py and pyreadstat with the same results. You might say that the problem is in the data but using an online tool to read sas7bdat the data seems correct.
Code for the other two libraries:
# pyreadstat module
import pyreadstat
df2, meta = pyreadstat.read_sas7bdat('test.sas7bdat')
# sas7bdat module
from sas7bdat import SAS7BDAT
reader = SAS7BDAT('test.sas7bdat')
df_sas = reader.to_data_frame()
If you want to try, (and you have a SAS license), you can create a .sas7bdat file with the following content:
column_1,column_2,column_3
11,20190129,5434
19,20190228,5236
59,20190328,10448
76,20190129,5434

Answer 1

Use sas7bdat.py instead. That typically preserves the dataset formats better.
IF a particular column is defined as character in the SAS dataset, then sas7bdat will read it as as string regardless of how the contents look like. As a lazy example, I created this dataset in SAS:
data test;
id = '1111111'; val = 1; output;
id = '2222222'; val = 2; output;
run;
And then ran the following Python code on it:
reader = SAS7BDAT('test.sas7bdat')
df = reader.to_data_frame()
print(df)
cols = reader.columns
for col in cols:
print(str(col.name) + " " + str(col.type))
Here is what I see:
id val
0 1111111 1.0
1 2222222 2.0
b'id' string
b'val' number
If you are looking to 'intelligently' convert numbers to strings based on context, then you may need to look elsewhere. Any SAS dataset reader is just going to read based on the format specified within the dataset at best.