根据Python中的字符将字符串切成两个不同长度的块

问题描述

所以我有一个看起来像这样的文件：

oak
elm
tulip
redbud
birch

/plants/

allium
bellflower
ragweed
switchgrass

我要做的就是将树木和草种分成两块，这样我就可以分别称呼它们：

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那样，数据块的长度不相等，因此我必须根据分隔符“ / plants /”进行分割。如果我尝试拼接，则数据现在仅由空格分隔：

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（就我的目的而言这是可以的），但它们仍不能分为两组：

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']

要删除我认为是问题的空白行，我尝试了以下操作：How do I remove blank lines from a string in Python? 而且我知道，类似地在这里也有人问过用字符分割字符串：Python: split a string by the position of a character

但是我对为什么不能将两者分开感到非常困惑。

解决方法

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，除了使用idx-1，idx + 2之外，您还可以使用其他方法（例如列表理解）删除空str

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