将列表列表（用逗号分隔的语句）展平为列表列表[重复]

Question

我有一份声明清单。每个语句都有许多其他语句，用逗号分隔。

gf = ['citrus fruit,black bread,margarine,ready soups', 'tropical 
fruit,yogurt,coffee, margarine', 'whole milk'] ## it has elements (lists with multiple items separated by EXTERNAL commas). 

我需要把它转换成：

gf_n = ['citrus fruit', 'black bread', 'margarine', 'ready soups', 'tropical fruit', 'yogurt', 'coffee', 'margarine','whole milk']

可以重复单个元素（单词或一组单词）。将来，我需要计算每个元素的频率（例如“柑橘类水果”）和每个两项组合的频率（例如“黑面包”和“人造黄油”）

这是我的代码，结果不是我需要的：

gf_list = list(gf.split(","))

gf_item = []

gf_item = [item for sublist in gf_list for item in sublist]

这是我得到的令人惊讶的结果（字母 - 不是文字）

['c', 'i', 't', 'r', 'u', 's', ' ', 'f', 'r', 'u'] # first 10 elements

我做错了什么？

解决方案（经过一段时间我想出了这个）：

for subl in lst:

    gf_item.append(subl.split(","))

Answer 1

 gf_item = [i.strip() for i in gf for i in i.split(',')]

使用生成器-

def flatten(x):
    if type(x) is str:
        for i in x.split(','):
            yield i.strip()
        return 
    try:
        for i in x:
            yield from flatten(i)
    except TypeError:
        yield x 

gf = ['citrus fruit,black bread,margarine,ready soups', 'tropical fruit,yogurt,coffee, margarine', 'whole milk']
gf_new = list(flatten(gf))

lst = [['alice', 'gun'], ['bob', 'tree', ' mot'],['cara']]
lst_new = list(flatten(lst))

print(gf_new)
print(lst_new)

输出：

['citrus fruit', 'black bread', 'margarine', 'ready soups', 'tropical fruit', 'yogurt', 'coffee', 'margarine', 'whole milk']
['alice', 'gun', 'bob', 'tree', 'mot', 'cara']

Answer 2

试试这个：

gf1 = str(gf).replace("[",'').replace("]",'').replace("'",'')
gf_n = [x.strip() for x in gf1.split(',')]

返回：

['citrus fruit',
 'black bread',
 'margarine',
 'ready soups',
 'tropical fruit',
 'yogurt',
 'coffee',
 'margarine',
 'whole milk']