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Given the following text problem statement, write Python code to implement the functionality described below in problem statement
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Problem:
What is an efficient way of splitting a column into multiple rows using dask dataframe? For example, let's say I have a csv file which I read using dask to produce the following dask dataframe:
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Python Code:
import pandas as pd
df = pd.DataFrame([["A", "Z,Y"], ["B", "X"], ["C", "W,U,V"]], index=[1,2,3], columns=['var1', 'var2'])
def g(df):
    return df.join(pd.DataFrame(df.var2.str.split(',', expand=True).stack().reset_index(level=1, drop=True),columns=['var2 '])).\
        drop('var2',1).rename(columns=str.strip).reset_index(drop=True)
result = g(df.copy())
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