ValueError：未知的URL类型：'h'

Question

Ok, so I'm trying my best to run this program, and I BELIEVE this function is the problem

urls = ('http://3.bp.blogspot.com/-SC-w7eTgpM0/URE9NsI_nuI/AAAAAAAAAGE/YmlWnimNuPM/s1600/7957178556_001939ffc5_z.jpg')
for addr in urls:
        get_img_from_web(addr)
images, names = scan_dir()
lum_values = []
for i in range(256):
        lum_values.append(i)
header = 'Jack Tompkins\n'+','.join(str(lum) for lum in lum_values)+'\n\n'
with open('p1TompkinsHistogram.csv', 'w') as f:
        f.write(header)
        for i, im in enumerate(images):
           data = get_data(im)
           path = names[i]
           last_slash = path.rfind('/')
           name = path[last_slash+1:]
           f.write(name +',' + im.mode + ',' + data + ',')
           h_r, h_g, h_b = get_histograms(im)
           f.write(get_histogram_data(h_r, h_g, h_b) + '\n')
           f.write(','.join(str(i) for i in h_r) + '\n')
           f.write(','.join(str(i) for i in h_g) + '\n')
           f.write(','.join(str(i) for i in h_b) + '\n')

`

This is the end of the error I get

raise ValueError("unknown url type: %r" % self.full_url)
ValueError:unknown url type: 'h'

Any thoughts?

Answer 1

Your problem is here:

urls = ('http://3.bp.blogspot.com/-SC-w7eTgpM0/URE9NsI_nuI/AAAAAAAAAGE/YmlWnimNuPM/s1600/7957178556_001939ffc5_z.jpg')
for addr in urls:

You meant to define urls as a tuple, but it is in fact a single string. Because the parentheses don't include any commas, Python sees it as a single expression to be evaluated, much as (2 + 2) is 4 and not a tuple containing 4. Strings are iterable and yield their constituent characters, so addr is each character from the string. So you try to open h , then t , then t , and so on. Or you would, if trying to open h didn't give you an error.

The solution is to write urls using a trailing comma, ensuring that Python sees it as a tuple, or to just use square brackets and make it a list. Or of course, use more than one item.