I have a dataframe with a column with item names and a column with a number. I would like to create a list with the item names repeated the number of times in the column.

My desired output is

I feel like I'm quite close with this code:

for index in df.iterrows():
    for x in range(2):
        print(df.item)

However, I can't find a way to replace 2 in range with the number out of the dataframe. df.numbers doesn't seem to work.

CodePudding user response：

As you said, your desired output is a list, using @Michael's comment, you can do this:

list(df.item.repeat(df.number))

The output would be:

['cat', 'cat', 'dog', 'dog', 'dog', 'parrot', 'parrot', 'parrot', 'parrot']

CodePudding user response：

If you were keen on using .iterrows() then you might do something like:

import pandas

df = pandas.DataFrame([
    {"item": "cat", "number": 2},
    {"item": "dog", "number": 3},
    {"item": "parrot", "number": 4},
])

new_list = []
for index, row in df.iterrows():
    new_list.extend([row["item"]] * row["number"])

print(new_list)

This relies on the fact that ["x"] * 3 === ["x", "x", "x"]