Limit of a file size when performing download from Box using Boxsdf

As per documentation I can use below code to download the file from Box

file_id = '11111'

# Write the Box file contents to disk
output_file = open('file.pdf', 'wb')
client.file(file_id).download_to(output_file)

It works fine for small size files but If I try the same for let's say a 5 mb plus file it fails.
The file gets downloaded but not readble

IIs there any limit on file size when downloading using above option ?
If yes, what is alternative can I download it in parts ?