1

I am new to Python. I have a data frame as shown below. This is a CSV file. I need to select all rows which contain Frequency values 0.8 and 0.6. I wrote the codes as shown but it is throwing an error.

df_new = df[df['Frequency'] == 0.8 & df['Frequency'] == 1.6 ]

Below is the last line from the error I received.

"TypeError: Cannot perform 'rand_' with a dtyped [float64] array and scalar of type [bool]"

I ran the below code

df_new = df[(df['Frequency'] == 0.8) & (df['Frequency'] == 1.6) ]

It is nt showing any error but values are not coming.it is showing only the name of columns .Please see the bwloe image

enter image description here

enter image description here

Improve this question
1
  • 2
    try, df[(df['Frequency'] == 0.8) & (df['Frequency'] == 1.6)] Commented Apr 30, 2021 at 10:06

5 Answers 5

Reset to default
2

add round bracket around the conditions

df_new = df[ (df['Frequency'] == 0.8) & (df['Frequency'] == 1.6) ]
Improve this answer
Sign up to request clarification or add additional context in comments.

2 Comments

I run this code.it is not showing any error . But o/p is not proper. Column names are coming but not the contents. I updated my question please see.
use OR instead of AND
2

Do you want this?

df_new = df[df['Frequency'].isin([0.8,1.6])]
Improve this answer

Comments

2

You are using & thats why you are getting an empty dataframe. Frequency can not be 0.8 and 0.6 at the same time. Use | instead.

Try this:

df = df[(df['Frequency'] == 0.8) | (df['Frequency'] == 0.6)]

OR

df = df[df["Frequency"].isin([0.6,0.8])]
Improve this answer

2 Comments

if you don't mind could you please tell me what is "isin" means?
isin() will match a value with list of values you provided. Lets say you want to compare frequency with 0.6, 0.8,1,2,3.. So writing individual condition will be a mess. You can simply provide all values to a list and use isin()
2

Its not showing an answer causer and condition is not matching. use OR instead of AND

df_new = df[ (df['Frequency'] == 0.8) | (df['Frequency'] == 1.6) ]
Improve this answer

Comments

1

You need add bracket because of the priority of & and ==

df_new = df[(df['Frequency'] == 0.8) & (df['Frequency'] == 1.6) ]
Improve this answer

1 Comment

I run this code.it is not showing any error . But o/p is not proper. Column names are coming but not the contents. I updated my question please see.

Start asking to get answers

Find the answer to your question by asking.

Ask question

Explore related questions

See similar questions with these tags.