在Python中动态分割复杂的字符串

Question

我一直在组织一个能够以我想要的方式处理字符串的函数.我已研究过了一把前面的问题1,2,3等等,我通过整理.这是设置,我有结构良好但可变的数据,需要从从文件读取的字符串拆分为字符串数组.以下展示了我正在处理的数据的一些示例

('Vdfbr76','gsdf','gsfd','',NULL),
('Vkdfb23l','gsfd','gsfg','ggg@df.gf',NULL),
('4asg0124e','Lead Actor/SFX MUA/Prop designer','John Smith','jsmith@email.com',NULL),
('asdguIux','Director, Camera Operator, Editor, VFX','John Smith','',NULL),
...
(492,'E1asegaZ1ox','Nysdag_5YmD','145872325372620',1,'long, string, with, commas'),

我想基于逗号分割这些字符串,但是,字符串中偶尔会包含逗号,这会导致问题.除此之外,re.split(regex, line)在整个读取过程中,每行中的项目数量变化变得困难.

到目前为止我已经尝试过一些解决方案.

def splitLine(text, fields, delimiter):
    return_line = []

    regex_string = "(.*?),"

    for i in range(0,len(fields)-1):

        regex_string+=("(.*)")

        if i < len(fields)-2:
            regex_string+=delimiter

    return_line = re.split(regex_string, text)

    return return_line

这将得到一个结果,我们有以下输出

 regex_string
 return_line

然而,这个问题的主要问题是它偶尔会将两个字段混为一谈.在数组中的第3个值的情况下.

(.*?),(.*),(.*),(.*),(.*),(.*)
['', '\t(222', "'Vy1asdfnuJkA','Ndfbyz3_YMD'", "'14541242640005471'", '2', "'Hello World!')", '', '\n']

理想的结果如下:

['', '\t(222', "'Vy1asdfnuJkA'", "'Ndfbyz3_YMD'", "'14541242640005471'", '2', "'Hello World!')", '', '\n']

这是一个很小的变化,但它对结果有很大的影响.我试着操纵正则表达式字符串以更好地适应我想要做的事情,但是每次我解决了,不幸的是另一个打破了它.

我玩的另一个案例来自用户Aaron Cronin在这篇文章4中,如下所示

def split_at(text, delimiter, opens='<([', closes='>)]', quotes='"\''):
result = []
buff = ""
level = 0
is_quoted = False

for char in text:
    if char in delimiter and level == 0 and not is_quoted:
        result.append(buff)
        buff = ""
    else:
        buff += char

        if char in opens:
            level += 1
        if char in closes:
            level -= 1
        if char in quotes:
            is_quoted = not is_quoted

if not buff == "":
    result.append(buff)

return result

结果如下:

["\t('Vk3NIasef366l','gsdasdf','gsfasfd','',NULL),\n"]

主要问题是它出现的是同一个字符串.这使我进入反馈循环.

理想的结果如下:

[\t('Vk3NIasef366l','gsdasdf','gsfasfd','',NULL),\n]

任何帮助表示赞赏,我不确定在这种情况下最好的方法是什么.我很乐意澄清任何出现的问题.我尽量做到尽可能完整.

Answer 1

用ast的literal_eval!

from ast import literal_eval

s = """('Vdfbr76','gsdf','gsfd','',NULL),
('Vkdfb23l','gsfd','gsfg','ggg@df.gf',NULL),
('4asg0124e','Lead Actor/SFX MUA/Prop designer','John Smith','jsmith@email.com',NULL),
('asdguIux','Director, Camera Operator, Editor, VFX','John Smith','',NULL),
(492,'E1asegaZ1ox','Nysdag_5YmD','145872325372620',1,'long, string, with, commas'),
"""

for line in s.split("\n"):
    line = line.strip().rstrip(",").replace("NULL", "None")
    if line:
        print list(literal_eval(line))  #list(..) is just an example

输出:

['Vdfbr76', 'gsdf', 'gsfd', '', None]
['Vkdfb23l', 'gsfd', 'gsfg', 'ggg@df.gf', None]
['4asg0124e', 'Lead Actor/SFX MUA/Prop designer', 'John Smith', 'jsmith@email.com', None]
['asdguIux', 'Director, Camera Operator, Editor, VFX', 'John Smith', '', None]
[492, 'E1asegaZ1ox', 'Nysdag_5YmD', '145872325372620', 1, 'long, string, with, commas']