根据Python中的字符将字符串分为两个不同长度的块

Question

我有一个文件，看起来像这样：

oak
elm
tulip
redbud
birch

/plants/

allium
bellflower
ragweed
switchgrass

我想做的就是把树木和草本植物分成两块，这样我就可以这样分别称它们：

print(trees)
oak
elm
tulip
redbud
birch

print(herbs)
allium
bellflower
ragweed
switchgrass

正如您在示例数据中看到的，数据块的长度不等，因此我必须根据分隔符“/plants/”进行分割。如果我尝试拼接，则数据现在仅以空格分隔：

for groups in plant_data:
    groups  = groups.strip()
    groups = groups.replace('\n\n', '\n')
    pos = groups.find("/plants/") 
    trees, herbs = (groups[:pos], groups[pos:])
print(trees)
oa
el
tuli
redbu
birc



alliu
bellflowe
ragwee
switchgras

如果我尝试简单地拆分，我会得到列表（这对我来说是可以的），但它们仍然没有被拆分为两组：

for groups in plant_data:
    groups  = groups.strip()
    groups = groups.replace('\n\n', '\n')
    trees = groups.split("/plants/")
print(trees)
['oak']
['elm']
['tulip']
['redbud']
['birch']
['']
['', '']
['']
['allium']
['bellflower']
['ragweed']
['switchgrass']

为了删除我认为是问题所在的空行，我尝试了以下方法：How do I remove blank lines from a string in Python? 我知道这里也有类似的问题：用一个字符拆分一个字符串：Python: split a string by the position of a character

但是我很困惑为什么我不能把这两个分开

Answer 1

spam = """oak
elm
tulip
redbud
birch

/plants/

allium
bellflower
ragweed
switchgrass"""

spam = spam.splitlines()
idx = spam.index('/plants/')
trees, herbs = spam[:idx-1], spam[idx+2:]   
print(trees)
print(herbs)

输出

['oak', 'elm', 'tulip', 'redbud', 'birch']
['allium', 'bellflower', 'ragweed', 'switchgrass']

当然，您可以使用不同的方法（例如列表理解）删除空str，而不是使用idx-1、idx+2

spam = [line for line in spam.splitlines() if line]
idx = spam.index('/plants/')
trees, herbs = spam[:idx], spam[idx+1:]