问题描述
我该如何使用'and'过滤数据框?换句话说，如果我有一个名为m的数据框，并且具有a，b，c，d，e列，我将如何返回b列中的值大于120且c列中的值等于7.3的所有行?
How would I filter a dataframe using 'and' ? In other words, if I have a dataframe named m and it has columns a,b,c,d,e, how would i return all rows where the values in column b are greater than 120 and the vales in column c = 7.3 ?
我尝试了这个，但是出现错误:
I tried this but I'm getting an error:
print(m [m ['b']> 120，m ['c'] == 7.3])
print(m[m['b'] >120, m['c'] ==7.3])
推荐答案
要扩展GoBrewers14的答案，您需要环绕括号以克服在python中对运算符求值的顺序.
To expand on GoBrewers14's answer, you need to wrap around parenthesis to overcome the order of evaluation of the operators in python.
例如，下一条语句失败:
For example, the next statement fails:
In [3]: 1 > 0 & 'a' < 'b'
---------------------------------------------------------------------------
TypeError Traceback (most recent call last)
<ipython-input-3-5d58a7b0bade> in <module>()
----> 1 1 > 0 & 'a' < 'b'
TypeError: unsupported operand type(s) for &: 'int' and 'str'
因为python首先计算0 & 'a'.这就是为什么您需要用括号将语句包装起来才有意义:
because python evaluates first 0 & 'a'. That's why you need to wrap the statements with parenthesis to make sense:
In [4]: (1 > 0) & ('a' < 'b')
Out[4]: True
简而言之，您正在寻找:
In short, you are looking for:
m[(m['b'] > 120) & (m['c'] == 7.3)]
这篇关于根据多列条件过滤DataFrame的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持！