CODEWITHSUNDEEP
pythonpandasfloating-pointscientific-notationnumber-formatting
horatio1701d
horatio1701d

Reputation: 9159

Format / Suppress Scientific Notation from Pandas Aggregation Results

How can one modify the format for the output from a groupby operation in pandas that produces scientific notation for very large numbers?

I know how to do string formatting in python but I'm at a loss when it comes to applying it here. 

df1.groupby('dept')['data1'].sum()

dept
value1       1.192433e+08
value2       1.293066e+08
value3       1.077142e+08

This suppresses the scientific notation if I convert to string but now I'm just wondering how to string format and add decimals. 

sum_sales_dept.astype(str)

Upvotes: 285

Views: 501493

Answers (8)

gibbone
gibbone

Reputation: 2700

Expanding on this useful comment, here is a solution setting the formatting options only to display the results without changing options permanently:

with pd.option_context('display.float_format', lambda x: f'{x:,.3f}'):
    display(sum_sales_dept)

dept
value1  119,243,300.0
value2  129,306,600.0
value3  107,714,200.0

Upvotes: 10

dabru
dabru

Reputation: 951

Setting a fixed number of decimal places globally is often a bad idea since it is unlikely that it will be an appropriate number of decimal places for all of your various data that you will display regardless of magnitude. Instead, try this which will give you scientific notation only for large and very small values (and adds a thousands separator unless you omit the ","):

pd.set_option('display.float_format', lambda x: '%,g' % x)

Or to almost completely suppress scientific notation without losing precision, try this:

pd.set_option('display.float_format', str)

Upvotes: 27

Full.Of.Life
Full.Of.Life

Reputation: 179

I had multiple dataframes with different floating point, so thx to Allans idea made dynamic length.

pd.set_option('display.float_format', lambda x: f'%.{len(str(x%1))-2}f' % x)

The minus of this is that if You have last 0 in float, it will cut it. So it will be not 0.000070, but 0.00007.

Upvotes: 8

florestan
florestan

Reputation: 4655

If you want to style the output of a data frame in a jupyter notebook cell, you can set the display style on a per-dataframe basis:

df = pd.DataFrame({'A': np.random.randn(4)*1e7})
df.style.format("{:.1f}")

enter image description here

See the documentation here.

Upvotes: 30

tfhans
tfhans

Reputation: 1901

Here is another way of doing it, similar to Dan Allan's answer but without the lambda function:

>>> pd.options.display.float_format = '{:.2f}'.format
>>> Series(np.random.randn(3))
0    0.41
1    0.99
2    0.10

or 

>>> pd.set_option('display.float_format', '{:.2f}'.format)

Upvotes: 190

Vlad Bezden
Vlad Bezden

Reputation: 89499

You can use round function just to suppress scientific notation for specific dataframe:

df1.round(4)

or you can suppress is globally by:

pd.options.display.float_format = '{:.4f}'.format

Upvotes: 49

evil242
evil242

Reputation: 41

If you would like to use the values, say as part of csvfile csv.writer, the numbers can be formatted before creating a list:

df['label'].apply(lambda x: '%.17f' % x).values.tolist()

Upvotes: 1

Dan Allan
Dan Allan

Reputation: 35235

Granted, the answer I linked in the comments is not very helpful. You can specify your own string converter like so.

In [25]: pd.set_option('display.float_format', lambda x: '%.3f' % x)

In [28]: Series(np.random.randn(3))*1000000000
Out[28]: 
0    -757322420.605
1   -1436160588.997
2   -1235116117.064
dtype: float64

I'm not sure if that's the preferred way to do this, but it works.

Converting numbers to strings purely for aesthetic purposes seems like a bad idea, but if you have a good reason, this is one way:

In [6]: Series(np.random.randn(3)).apply(lambda x: '%.3f' % x)
Out[6]: 
0     0.026
1    -0.482
2    -0.694
dtype: object

Upvotes: 417

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