找出对象列在熊猫中是否具有多种数据类型的最快和/或最惯用的方法是什么？

Question

I have a dataframe with a column like this:

df.Chromosome
# 0        1
# 1        1
# 2        1
# 3        1
# 4        1
#         ..
# 94391    Y
# 94392    Y
# 94393    Y
# 94394    Y
# 94395    Y
# Name: Chromosome, Length: 94396, dtype: object

By doing df.Chromosome.apply(type).drop_duplicates() I find that it consists of two types of data:

0        <class 'int'>
65536    <class 'str'>
Name: Chromosome, dtype: object

Is there a faster and more idiomatic way of checking whether a column consists of multiple dtypes?

Answer 1

I think your solution is nice, another alternatives:

df.Chromosome.map(type).unique()

---

set(df.Chromosome.map(type))

Also is possible first remove duplicates in values for improve performance:

df.Chromosome.drop_duplicates().apply(type).drop_duplicates()

Answer 2

您也可以：

df.applymap(type).drop_duplicates()

Answer 3

Another alternative -

{type(_) for _ in set(df.Chromosome.value_counts().index)}

This is quite slow