pandas Python 等效于 R 运算符“%in%”

Python equivalent of the R operator "%in%"

提问by wolfsatthedoor

What is the python equivalent of this in operator? I am trying to filter down a pandas database by having rows only remain if a column in the row has a value found in my list.

运算符中 this 的 Python 等价物是什么？我试图通过仅当行中的列在我的列表中找到值时才保留行来过滤 Pandas 数据库。

I tried using any() and am having immense difficulty with this.

我尝试使用 any() 并且在这方面遇到了巨大的困难。

回答by Jeff

Pandas comparison with R docs are here.

Pandas 与 R 文档的比较在这里。

s <- 0:4
s %in% c(2,4)

The isin() method is similar to R %in% operator:

isin() 方法类似于 R %in% 运算符：

In [13]: s = pd.Series(np.arange(5),dtype=np.float32)

In [14]: s.isin([2, 4])
Out[14]: 
0    False
1    False
2     True
3    False
4     True
dtype: bool

回答by data_steve

FWIW: without having to call pandas, here's the answer using a for loopand list compressionin pure python

FWIW：无需调用Pandas，这是在纯 python 中使用 afor loop和的答案list compression

x = [2, 3, 5] 
y = [1, 2, 3]

# for loop
for i in x: [].append(i in y)

Out: [True, True, False]


# list comprehension
[i in y for i in x]

Out: [True, True, False]

回答by stok

As others indicate, inoperator of base Python works well.

正如其他人所指出的，in基本 Python 的运算符运行良好。

myList = ["a00", "b000", "c0"]

"a00" in myList
# True

"a" in myList
# False