Assign pandas dataframe column dtypes

Question

I want to set the dtypes of multiple columns in pd.Dataframe (I have a file that I\'ve had to manually parse into a list of lists, as the file was

Answer 1

You're better off using typed np.arrays, and then pass the data and column names as a dictionary.

import numpy as np
import pandas as pd
# Feature: np arrays are 1: efficient, 2: can be pre-sized
x = np.array(['a', 'b'], dtype=object)
y = np.array([ 1 ,  2 ], dtype=np.int32)
df = pd.DataFrame({
   'x' : x,    # Feature: column name is near data array
   'y' : y,
   }
 )