如何正确编制unicode d表格

Question

（我使用python2.7）

我有个测试：

# -*- coding: utf-8 -*-

import binascii

test_cases = [
    'aaaaa',    # Normal bytestring
    'ááááá',    # Normal bytestring, but with extended ascii. Since the file is utf-8 encoded, this is utf-8 encoded
    'ℕℤℚℝℂ',    # Encoded unicode. The editor has encoded this, and it is defined as string, so it is left encoded by python
    u'aaaaa',   # unicode object. The string itself is utf-8 encoded, as defined in the "coding" directive at the top of the file
    u'ááááá',   # unicode object. The string itself is utf-8 encoded, as defined in the "coding" directive at the top of the file
    u'ℕℤℚℝℂ',   # unicode object. The string itself is utf-8 encoded, as defined in the "coding" directive at the top of the file
]
FORMAT = '%-20s -> %2d %-20s %-30s %-30s'
for data in test_cases :
    try:
        hexlified = binascii.hexlify(data)
    except:
        hexlified = None
    print FORMAT % (data, len(data), type(data), hexlified, repr(data))

产生输出：

^{pr2}$

如您所见，对于包含非ascii字符的字符串，列没有正确对齐。这是因为这些字符串的长度（以字节为单位）大于unicode字符的数量。如何告诉print在填充字段时考虑字符数，而不是字节数？在

Answer 1

当Python2.7看到'ℕℤℚℝℂ'时，它读到“这里有15个任意字节值”。它不知道它们代表什么字符，也不知道它们代表它们的编码。您需要将此字节字符串解码为unicode字符串，并指定编码，然后才能期望python能够计算字符数：

for data in test_cases :
    if isinstance(data, bytes):
        data = data.decode('utf-8')
    print FORMAT % (data, len(data), type(data), repr(data))

注意，在python3中，所有字符串文本都是默认的unicode对象