How to use Pandas with float values

Question

I have data from csv:

36849|17|4.7|20180118103240
36792|17|5.3|20180118103238

4.7 and 5.3 is float

But when I do like this:

scores_data_train = pd.read_csv('../Dataset/TrainData//u.score.csv', sep='|')
scores_train = scores_data_train.as_matrix()
print(scores_train[:1, :])

The result:

[[3.68490000e+04 1.70000000e+01 4.70000000e+00 2.01801181e+13]]

Please help me. Thank you

Why are you using `as_matrix`? What's the intention here? It looks like the result is exactly correct. What is the problem? — rafaelc, Apr 01 '19 at 16:02

vrana95 · Answer 1 · 2019-04-01T16:09:57.590

0

Please do the below settings after importing numpy. refer similar questions, please check

   import numpy as np  
   np.set_printoptions(suppress=True,
   formatter={'float_kind':'{:0.2f}'.format})

#float, 2 units #precision right, 0 on left

edited Apr 01 '19 at 16:09

answered Apr 01 '19 at 15:29

vrana95

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2
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The pandas option will not affect the output format of the numpy array returned by `.as_matrix()` - after that point, it's basically out of pandas's hands. – Christoph Burschka Apr 01 '19 at 15:35
idea was to use it before converting to a matrix. Will that not work ? – vrana95 Apr 01 '19 at 15:56
Unfortunately not - the option only takes effect when floats inside a pandas dataframe are formatted to strings. Calling `.as_matrix()` will turn the dataframe into an array of floats, so pandas display formatting doesn't come into play. – Christoph Burschka Apr 01 '19 at 15:58

score 0 · Answer 2 · answered Apr 01 '19 at 15:31

The as_matrix() method turns the dataframe into a numpy array, which is limited to a single datatype by definition. You can't have some of the elements treated as floats while others are integers.

As long as you do not call .as_matrix(), you will have a dataframe, which can have integer and float columns. The types for each column can be specified by calling pd.read_csv(..., dtype={"colname": "int", "colname2": "float"}).

How to use Pandas with float values

2 Answers2