为什么我的列表在使用拆分函数后是空的？

Question

我正在尝试将和灌木从给定的数据中分离出来，形成两个单独的列表。这是我的代码：

data = ["Andromeda - Shrub","Bellflower - Flower","China Pink - Flower","Daffodil - Flower","Evening Primrose - Flower","French Marigold - Flower","Hydrangea - Shrub","Iris - Flower","Japanese Camellia - Shrub","Lavender - Shrub","Lilac- Shrub","Magnolia - Shrub","Peony - Shrub","Queen Anne's Lace - Flower","Red Hot Poker - Flower","Snapdragon - Flower","Sunflower - Flower","Tiger Lily - Flower","Witch Hazel - Shrub"]

flowers = []
shrubs = []

for i in data:
    x=i.split("-")
    print(x)
    if "Shrub" in x:
        shrubs.extend(x)
    elif "Flower" in x:
        flowers.extend(x)
print(shrubs)
print(flowers)

，灌木，和的名单显示是空的。为什么？?

Answer 1

当您按连字符拆分时，您需要查看第二项。您还应该在append上使用list extend方法，这样就不会追加字符序列。

data = ["Andromeda - Shrub","Bellflower - Flower","China Pink - Flower","Daffodil - Flower","Evening Primrose - Flower","French Marigold - Flower","Hydrangea - Shrub","Iris - Flower","Japanese Camellia - Shrub","Lavender - Shrub","Lilac- Shrub",        "Magnolia - Shrub","Peony - Shrub","Queen Anne's Lace - Flower","Red Hot Poker - Flower","Snapdragon - Flower","Sunflower - Flower","Tiger Lily - Flower","Witch Hazel - Shrub"]

flowers = []
shrubs = []

for i in data:
   flower, flower_type = i.split("-")
   print(flower)
   if "Shrub" in flower_type:
       shrubs.append(flower)
   elif "Flower" in flower_type:
       flowers.append(flower)

print("Shrubs")
print(shrubs)
print("Flowers")
print(flowers)

使用i.split(" - ")会更好，但是只有一个条目“Lilac-灌木”与之不匹配，如果这不仅仅是一个错误，那么修复它，然后使用i.split(" - ")来获得更干净的字符串。

Answer 2

正如蒂埃里·莱斯维尔所指出的，你还有空白。试着先替换所有的空白：

for i in data:
    i.replace(" ", "")
    x=i.split("-")

Answer 3

您可以使用Python的strip方法从无用的空格中清除数据：

data = ["Andromeda - Shrub","Bellflower - Flower","China Pink - Flower","Daffodil - Flower","Evening Primrose - Flower","French Marigold - Flower","Hydrangea - Shrub","Iris - Flower","Japanese Camellia - Shrub","Lavender - Shrub","Lilac- Shrub","Magnolia - Shrub","Peony - Shrub","Queen Anne's Lace - Flower","Red Hot Poker - Flower","Snapdragon - Flower","Sunflower - Flower","Tiger Lily - Flower","Witch Hazel - Shrub"]

flowers = []
shrubs = []

for i in data:
    x = [elm.strip() for elm in i.split("-")]

    print(x)

    if "Shrub" in x:
        shrubs.extend(x)
    elif "Flower" in x:
        flowers.extend(x)

print(shrubs)
print(flowers)