[英]Case insensitive filtering multiple columns in pandas using .loc
我想搜索忽略案例差异的值。 因此,例如,如果我输入“fred”,我仍然能够过滤所有包含 Fred 的值,即使 F 是大写的。
这就是我目前拥有的:
def find(**kwargs):
result = data.loc[data.rename(columns={"FirstName": "first",
"LastName": "last",
"City": "city",
})[list(kwargs.keys())]
.eq(list(kwargs.values())).all(axis=1)]
return result
但是,我意识到我不能在任何时候使用 .lower() 强制小写我传入的字符串和我过滤的值
这是我的数据示例:
FirstName LastName City
Fred Bob Austin
Billy Bob NYC
当我运行我的函数时,我期望这样:
find('fred')
Output: Fred Bob Austin
import pandas as pd
data = pd.DataFrame({"FirstName": ['Fred', 'Billy'], 'LastName':['Bob','Bob'], 'City': ['A', 'D']} )
def find(**kwargs):
result = data.loc[data.rename(columns={"FirstName": "first",
"LastName": "last",
"City": "city",
})[list(kwargs.keys())].apply(lambda x: x.str.lower()).eq(list(kwargs.values())).all(axis=1)]
return result
print(find(first='fred'))
回报
FirstName LastName City
0 Fred Bob A
这里有两种方法可以完成我相信你已经问过的事情,即:
first
、 last
和city
的任意组合对 df 列FirstName
、 LastName
和City
进行不区分大小写的过滤。方式#1
import pandas as pd
def find(**kwargs):
df = ( data.rename(columns={"FirstName": "first",
"LastName": "last",
"City": "city",
})[list(kwargs.keys())]
.apply(lambda x: x.str.lower(), axis=1) )
mask = df.eq(list(val.lower() for val in kwargs.values())).all(axis=1)
return data[mask]
data = pd.DataFrame({'FirstName':['Fred','Billy'],'LastName':['Bob','Bob'],'City':['Austin','NYC']})
方式#2
import pandas as pd
from operator import and_
from functools import reduce
def find(**kwargs):
df = data.rename(columns={"FirstName": "first",
"LastName": "last",
"City": "city",
})[list(kwargs.keys())]
valsLower = pd.Series([val.lower() for val in kwargs.values()], index=kwargs.keys())
mask = reduce(and_, (df[col].str.lower() == valsLower[col] for col in df.columns))
return data[mask]
data = pd.DataFrame({'FirstName':['Fred','Billy'],'LastName':['Bob','Bob'],'City':['Austin','NYC']})
测试代码:
print( '',"data",data,sep='\n' )
print( '',"first='fred'",find(first='fred'),sep='\n' )
print( '',"first='fReD'",find(first='fred'),sep='\n' )
print( '',"last='bob'",find(last='bob'),sep='\n' )
print( '',"city='austin'",find(city='austin'),sep='\n' )
print( '',"first='fred', city='austin'",find(first='fred', city='austin'),sep='\n' )
print( '',"city='austin', first='fred'",find(first='fred', city='austin'),sep='\n' )
print( '',"last='bob', city='austin'",find(last='bob', city='austin'),sep='\n' )
print( '',"first='billy', city='austin'",find(first='billy', city='austin'),sep='\n' )
示例输出:
data
FirstName LastName City
0 Fred Bob Austin
1 Billy Bob NYC
first='fred'
FirstName LastName City
0 Fred Bob Austin
first='fReD'
FirstName LastName City
0 Fred Bob Austin
last='bob'
FirstName LastName City
0 Fred Bob Austin
1 Billy Bob NYC
city='austin'
FirstName LastName City
0 Fred Bob Austin
first='fred', city='austin'
FirstName LastName City
0 Fred Bob Austin
city='austin', first='fred'
FirstName LastName City
0 Fred Bob Austin
last='bob', city='austin'
FirstName LastName City
0 Fred Bob Austin
first='billy', city='austin'
Empty DataFrame
Columns: [FirstName, LastName, City]
Index: []
使用match
功能。
import re
from functools import reduce
def find(df, **kwargs):
# Using AND condition. Modify & to | for OR condition.
cond = reduce(lambda prev, x: prev & df[x[0]].str.match(f'{x[1]}', flags=re.IGNORECASE),
kwargs.items(),
True)
return df[cond]
find(df, FirstName='fre', LastName='bob')
# FirstName LastName City
# 0 Fred Bob Austin
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