<human>:  reorganise a data frame.
<bot>:})

# Calling the function
df = reorganise_dataframe(df, 'col1', 'new_col1')

# Printing the data frame
print(df)

#Example Output
#  col2 new_col1
# 0   4     1
# 1   5     2
# 2   6     3

#Remember to inspect code for bugs.