Cool little utility to build Django model definitions from a CSV file. Outputs CharField definitions, with blank=True for columns that have blank cells, and max_length corresponding to the next power of 2 greater than that column's actual max length.

output.txt

Sample output:

processed 65534 lines
[(False, 10), (False, 12), (True, 908)]
field_one = models.CharField(max_length=16)
field_two = models.CharField(max_length=16)
field_three = models.CharField(max_length=1024, blank=True)

properties.py

import csv

with open('my.csv', 'rb') as f:
    reader = csv.reader(f)
    header = reader.next() # burn off the header
    props = [(False, 0)] * 3 # 3 is number of columns
    for n, line in enumerate(reader):
        for i, item in enumerate(line):
            item = item.strip()
            if not item:
                props[i] = (True, props[i][1])
            if len(item) > props[i][1]:
                props[i] = (props[i][0], len(item))
    print 'processed %s lines' % n
    print props

    for i, p in enumerate(props):
        power = 0
        while 2 ** power < p[1]:
            power += 1
        max_length = 2 ** power
        if p[0]:
            print '%s = models.CharField(max_length=%s, blank=True)' % (header[i], max_length)
        else:
            print '%s = models.CharField(max_length=%s)' % (header[i], max_length)

lol hero. found this because i'm bouta have to make model based on a csv. thanks.

Here's the script that's compatible with Python >=3.6. It also has a dynamic number of headers:

import csv

with open('data.csv') as f:
    reader = csv.reader(f)
    header = next(reader) # burn off the header
    props = [(False, 0)] * len(header) #() # 3 is number of columns
    for n, line in enumerate(reader):
        for i, item in enumerate(line):
            item = item.strip()
            if not item:
                props[i] = (True, props[i][1])
            if len(item) > props[i][1]:
                props[i] = (props[i][0], len(item))
    print(f'processed {n} lines')
    print(props)

    for i, p in enumerate(props):
        power = 0
        while 2 ** power < p[1]:
            power += 1
        max_length = 2 ** power
        model_name = header[i]
        if p[0]:
            print(f'{model_name} = models.CharField(max_length={max_length})')
        else:
            print(f'{model_name} = models.CharField(max_length={max_length})')