Question

我有3个长度为n的列表，想要合并为一个列表，然后将所有第n个索引合并到一个列表中，并在csv文件的单独列中生成每个元素的输出结果

list_1 = ["john", "peter", "steve", "mike", "paul"]
list_2 = ["green", "red", "blue", "purple", "orange"]
list_3 = [["dog", "cat"], "rabbit", "dog", "", ["cat", "mouse", "elephant"]

到目前为止，我已经使用过：

combined_list = list(map(list, zip(list_1, list_2, list_3)))

将列表合并为一个。

如果我尝试：

for items in combined_list:
    writer.writerow(items)

我得到：

john,green,"['dog', 'cat']"
peter,red,rabbit
steve,blue,dog
mike,purple,
paul,orange,"['cat', 'mouse', 'elephant']"

预期输出：

john, green, dog, cat
peter, red, rabbit
steve, blue, dog
mike, purple, 
paul, orange, cat, mouse, elephant

（每个元素在单独的列中）

Answer 1

使用isinstance检查最后一项是否为列表（如果是，则扩展），否则按原样使用列表。

例如：

list_1 = ["john", "peter", "steve", "mike", "paul"]
list_2 = ["green", "red", "blue", "purple", "orange"]
list_3 = [["dog", "cat"], "rabbit", "dog", "", ["cat", "mouse", "elephant"]]

combined_list = list(map(list, zip(list_1, list_2, list_3)))
for items in combined_list:
    if isinstance(items[-1], list):              #Check if last element is list. 
        writer.writerow(items[:-1] + items[-1])
    else:
        writer.writerow(items)

Answer 2

这是使用带有条件的双列表理解的另一种方法：

list_1 = ["john", "peter", "steve", "mike", "paul"]
list_2 = ["green", "red", "blue", "purple", "orange"]
list_3 = [["dog", "cat"], "rabbit", "dog", "", ["cat", "mouse", "elephant"]]
combined_list = list(map(list, zip(list_1, list_2, list_3)))

# This function will help us differentiate strings from lists
def length(y):
    if isinstance(y, str):
        return 'i'
    else:
        return y

# We will store the lists inside a dictionnary
lists = {}
for i in range (len(list_1)):
    # If we have a string we store the string otherwise we iterate
    # on the list
    lists[i] = [y if isinstance(y, str) else x 
                for y in combined_list[i] for x in length(y)]

输出：

{0: ['john', 'green', 'dog', 'cat'],
 1: ['peter', 'red', 'rabbit'],
 2: ['steve', 'blue', 'dog'],
 3: ['mike', 'purple', ''],
 4: ['paul', 'orange', 'cat', 'mouse', 'elephant']}

Answer 3

list_1 = ["john", "peter", "steve", "mike", "paul"]
list_2 = ["green", "red", "blue", "purple", "orange"]
list_3 = [["dog", "cat"], "rabbit", "dog", "", ["cat", "mouse", "elephant"]]
alllist=[[l1,l2,l3] for l1,l2,l3 in zip(list_1,list_2,list_3)]

for l in alllist:
 re=[]
 [re.extend(item) if isinstance(item,list) else re.append(item) for item in l]
 print(",".join(re))

结果

john,green,dog,cat
peter,red,rabbit
steve,blue,dog
mike,purple,
paul,orange,cat,mouse,elephant

将嵌套列表的每个元素写入CSV的单独列中

3 个答案: