[英]Python - occurrence of substring in a list of lists
我正在使用一個函數,該函數將在列表列表中搜索子字符串,作為列表中每個項目的前三個字符。 例如,如果子字符串為'aaa'
,並且列表列表為[['aaa111', 'aba123', 'aaa123'], ['aaa302', 'cad222']]
,則我希望該函數返回a百分比列表[66, 50]
,因為'aaa'
在第一個列表中出現2/3次,在第二個列表中出現1/2次。 到目前為止,我有:
def percentage(list_of_lists, substring):
count = 0
percentage = []
for item in list_of_lists:
for i in item:
if substring == i[0:3]:
count += 1
percentage.append(int(count / len(item) * 100))
return percentage
我了解我的代碼可能過多,但是我只是了解Python的要點,所以我並不擔心。
>>> percentage([['aaa111', 'aba123', 'aaa123'], ['aaa302', 'cad222']], 'aaa')
[66, 150]
如何使其在list_of_lists中按列表進行計數?
兩件事情...
count
我改變了count
-> 0.0
def percentage(list_of_lists, substring):
percentage = []
for item in list_of_lists:
count = 0.0
for i in item:
if substring == i[0:3]:
count += 1
percentage.append(int(count / len(item) * 100))
return percentage
# Test
In [17]: l = [['aaa111', 'aba123', 'aaa123'], ['aaa302', 'cad222']]
In [18]: s = 'aaa'
In [19]: percentage(l,s)
Out[19]: [66, 50]
使用lambda
和map
函數的解決方案:
>>> [(sum(map(lambda z: "aaa" in z,z))*100/len(z)) for z in [y for y in [['aaa111', 'aba123', 'aaa123'], ['aaa302', 'cad222']]]]
[66, 50]
修改后的代碼對我有用:
def percentage(list_of_lists, substring):
count = 0
percentage = []
for item in list_of_lists:
for i in item:
if substring == i[0:3]:
count += 1
percentage.append(int(count / len(item) * 100))
count = 0
return percentage
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