Python字符串表示法让您感到困惑.

You are getting confused by the Python string representation.

打印python列表(或任何其他标准的Python容器)时，内容以特殊表示形式显示，从而使调试更加容易；显示的每个值都是在 repr()函数上调用的结果那个价值.对于字符串值，这意味着结果是 unicode字符串表示形式，这与直接打印字符串时看到的东西不同.

When you print a python list (or any other standard Python container), the contents are shown in special representation to make debugging easier; each value is shown is the result of calling the repr() function on that value. For string values, that means the result is a unicode string representation, and that is not the same thing as what you see when the string is printed directly.

Unicode和字节字符串在显示时表示为字符串文字；带引号的值，您可以将这些值直接复制并粘贴回Python代码中，而不必担心编码；任何非可打印ASCII字符的内容均以引号引起来.超出latin-1平面的Unicode代码点显示为'\u....'转义序列.拉丁1范围内的字符使用'\x..转义序列.许多控制字符以1个字母的转义形式显示，例如\n和\t.

Unicode and byte strings, when shown like that, are presented as string literals; quoted values that you can copy and paste straight back into Python code without having to worry about encoding; anything that is not a printable ASCII character is shown in quoted form. Unicode code points beyond the latin-1 plane are shown as '\u....' escape sequences. Characters in the latin-1 range use the '\x.. escape sequence. Many control characters are shown in their 1-letter escape form, such as \n and \t.

python交互式提示执行相同的操作；当您使用print在提示符上不带的值上回显一个值时，表示"中的值以repr()形式显示:

The python interactive prompt does the same thing; when you echo a value on the prompt without using print, the value in 'represented', shown in the repr() form:

>>> print u'\u2036Hello World!\u2033'
‶Hello World!″
>>> u'\u2036Hello World!\u2033'
u'\u2036Hello World!\u2033'
>>> [u'\u2036Hello World!\u2033', u'Another\nstring']
[u'\u2036Hello World!\u2033', u'Another\nstring']
>>> print _[1]
Another
string

这是完全正常的行为.换句话说，您的代码有效，没有任何问题.

This entirly normal behaviour. In other words, your code works, nothing is broken.

回到代码，如果您只想从tweet JSON结构中提取'text'键，请在读取文件时进行过滤，而不必为循环两次而烦恼:

To come back to your code, if you want to extract just the 'text' key from the tweet JSON structures, filter while reading the file, don't bother with looping twice:

import json

with open("file_name.txt") as tweets_file:
    tweets = [] 
    for line in tweets_file:
        data = json.loads(a)
        if 'text' in data:
            tweets.append(data['text'])