import numpy as np
import pandas as pd
file_path = 'test_file.csv'

n_rows = 1500000
n_digits = 19
target_size = 1.5*1024*1024 # 1.5 gigabytes
n_columns = int(1.5*1024*1024/n_rows/n_digits)

df = pd.DataFrame(np.random.randn(n_rows,n_columns), columns=[hex(x) for x in range(0,n_columns)])
df.to_csv('test_file.csv', index=False)