Python – How to get the row count of a Pandas DataFrame

dataframepandaspython

I'm trying to get the number of rows of dataframe df with Pandas, and here is my code.

Method 1:

total_rows = df.count
print total_rows + 1

Method 2:

total_rows = df['First_columnn_label'].count
print total_rows + 1

Both the code snippets give me this error:

TypeError: unsupported operand type(s) for +: 'instancemethod' and 'int'

What am I doing wrong?

Best Solution

For a dataframe df, one can use any of the following:

len(df.index)
df.shape[0]
df[df.columns[0]].count() (== number of non-NaN values in first column)

Code to reproduce the plot:

import numpy as np
import pandas as pd
import perfplot

perfplot.save(
    "out.png",
    setup=lambda n: pd.DataFrame(np.arange(n * 3).reshape(n, 3)),
    n_range=[2**k for k in range(25)],
    kernels=[
        lambda df: len(df.index),
        lambda df: df.shape[0],
        lambda df: df[df.columns[0]].count(),
    ],
    labels=["len(df.index)", "df.shape[0]", "df[df.columns[0]].count()"],
    xlabel="Number of rows",
)

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And just the time:

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See the documentation for more information.

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Python – Create a Pandas Dataframe by appending one row at a time

You can use df.loc[i], where the row with index i will be what you specify it to be in the dataframe.

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>>> from numpy.random import randint

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