How to Read In Pandas Column As Column Of Lists?

To read a column in pandas as a column of lists, you can use the apply method along with the lambda function. By applying a lambda function to each element in the column, you can convert the values into lists. This way, you can read a column in pandas as a column of lists.

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How to read in pandas column as column of lists in Python?

You can read a column in pandas as a column of lists by using the read_csv() function and specifying the converters parameter to convert the column into a list. Here's an example:

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import pandas as pd

# Create a sample dataframe
data = {
    'column_with_lists': ['[1, 2, 3]', '[4, 5, 6]', '[7, 8, 9]']
}
df = pd.DataFrame(data)

# Define a function to convert string representation of lists into lists
def convert_to_list(lst_str):
    return eval(lst_str)

# Read the column as a column of lists
df['column_with_lists'] = df['column_with_lists'].apply(convert_to_list)

# Print the dataframe
print(df)

In this example, we have a column called column_with_lists with string representations of lists. We define a function convert_to_list that converts each string representation into a list using the eval() function. We then apply this function to the column using the apply() method, which converts the column into a column of lists.

How to concatenate pandas columns into a single column of lists?

You can concatenate multiple columns in a DataFrame into a single column of lists by using the apply method along with a lambda function. Here's an example:

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import pandas as pd

# Sample DataFrame
df = pd.DataFrame({'A': [1, 2, 3],
                   'B': [4, 5, 6],
                   'C': [7, 8, 9]})

# Concatenate columns A, B, and C into a single column of lists
df['combined'] = df.apply(lambda row: [row['A'], row['B'], row['C']], axis=1)

print(df)

This will create a new column called 'combined' in the DataFrame df which contains lists of values from columns A, B, and C for each row.

Output:

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   A  B  C      combined
0  1  4  7  [1, 4, 7]
1  2  5  8  [2, 5, 8]
2  3  6  9  [3, 6, 9]

You can adjust the lambda function as needed to concatenate specific columns or customize the list output.

What is the maximum number of lists that can be stored in a pandas column?

There is no specific limit to the number of lists that can be stored in a pandas column. The maximum number of lists that can be stored will depend on the available memory of the system. However, it is generally recommended to avoid storing large numbers of lists in a single column as it can impact performance and memory usage.