CODEWITHSUNDEEP
pythonlistreplaceexpression
pnkjmndhl
pnkjmndhl

Reputation: 585

change values in a list based on its existing values

I have a list that has the data types of a dataframe. I would like to change the values in the list based on the existing values.

list = [dtype('int64'), dtype('int64'), dtype('int64'), dtype('int64'), dtype('int64'), dtype('int64'), dtype('int64'), dtype('int64'), dtype('int64'), dtype('int64'), dtype('int64'), dtype('int64'), dtype('int64'), dtype('int64'), dtype('int64'), dtype('int64'), dtype('int64'), dtype('int64'), dtype('float64'), dtype('float64'), dtype('float64'), dtype('float64'), dtype('float64'), dtype('float64')]

I want a new list whose values are "Double" for values "dtype('float64')" and "Long" for anything else. I tried this expression but doesn't work.

listnew = ["Double" if x == "dtype('float64')" else "Long" for x in list]

Upvotes: 0

Views: 48

Answers (1)

Erick Shepherd
Erick Shepherd

Reputation: 1443

Try the following:

import numpy as np

list_ = [np.dtype(np.int64) for n in range(18)] + [np.dtype(np.float64) for n in range(6)]

listnew = ["Double" if np.dtype(x) == np.dtype(np.float64) else "Long" for x in list_]

print(listnew)

Where 

list_ = [np.dtype(np.int64) for n in range(18)] + [np.dtype(np.float64) for n in range(6)]

is equivalent to your given list:

list_ = [np.dtype(np.int64),   np.dtype(np.int64),   np.dtype(np.int64),   \
         np.dtype(np.int64),   np.dtype(np.int64),   np.dtype(np.int64),   \
         np.dtype(np.int64),   np.dtype(np.int64),   np.dtype(np.int64),   \
         np.dtype(np.int64),   np.dtype(np.int64),   np.dtype(np.int64),   \
         np.dtype(np.int64),   np.dtype(np.int64),   np.dtype(np.int64),   \
         np.dtype(np.int64),   np.dtype(np.int64),   np.dtype(np.int64),   \
         np.dtype(np.float64), np.dtype(np.float64), np.dtype(np.float64), \
         np.dtype(np.float64), np.dtype(np.float64), np.dtype(np.float64)]

And the output when printing listnew is the following list:

['Long', 'Long', 'Long', 'Long', 'Long', 'Long', 'Long', 'Long', 'Long', 'Long', 'Long', 'Long', 'Long', 'Long', 'Long', 'Long', 'Long', 'Long', 'Double', 'Double', 'Double', 'Double', 'Double', 'Double']

Upvotes: 1

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