To select columns that are only of numeric datatype from a Pandas DataFrame, call DataFrame. select_dtypes() method and pass np. number or 'number' as argument for include parameter.
We can use select_if() function to get numeric columns by calling the function with the dataframe name and isnumeric() function that will check for numeric columns.
You can get the number of rows in Pandas DataFrame using len(df. index) and df. shape[0] properties. Pandas allow us to get the shape of the DataFrame by counting the number of rows in the DataFrame.
You could use select_dtypes
method of DataFrame. It includes two parameters include and exclude. So isNumeric would look like:
numerics = ['int16', 'int32', 'int64', 'float16', 'float32', 'float64']
newdf = df.select_dtypes(include=numerics)
Simple one-line answer to create a new dataframe with only numeric columns:
df.select_dtypes(include=np.number)
If you want the names of numeric columns:
df.select_dtypes(include=np.number).columns.tolist()
Complete code:
import pandas as pd
import numpy as np
df = pd.DataFrame({'A': range(7, 10),
'B': np.random.rand(3),
'C': ['foo','bar','baz'],
'D': ['who','what','when']})
df
# A B C D
# 0 7 0.704021 foo who
# 1 8 0.264025 bar what
# 2 9 0.230671 baz when
df_numerics_only = df.select_dtypes(include=np.number)
df_numerics_only
# A B
# 0 7 0.704021
# 1 8 0.264025
# 2 9 0.230671
colnames_numerics_only = df.select_dtypes(include=np.number).columns.tolist()
colnames_numerics_only
# ['A', 'B']
You can use the undocumented function _get_numeric_data()
to filter only numeric columns:
df._get_numeric_data()
Example:
In [32]: data
Out[32]:
A B
0 1 s
1 2 s
2 3 s
3 4 s
In [33]: data._get_numeric_data()
Out[33]:
A
0 1
1 2
2 3
3 4
Note that this is a "private method" (i.e., an implementation detail) and is subject to change or total removal in the future. Use with caution.
df.select_dtypes(exclude = ['object'])
Update:
df.select_dtypes(include= np.number)
or with new version of panda
df.select_dtypes('number')
Simple one-liner:
df.select_dtypes('number').columns
Following codes will return list of names of the numeric columns of a data set.
cnames=list(marketing_train.select_dtypes(exclude=['object']).columns)
here marketing_train
is my data set and select_dtypes()
is function to select data types using exclude and include arguments and columns is used to fetch the column name of data set
output of above code will be following:
['custAge',
'campaign',
'pdays',
'previous',
'emp.var.rate',
'cons.price.idx',
'cons.conf.idx',
'euribor3m',
'nr.employed',
'pmonths',
'pastEmail']
If you love us? You can donate to us via Paypal or buy me a coffee so we can maintain and grow! Thank you!
Donate Us With