How to add a trailing zeros to a pandas dataframe column?

Question

I have a pandas dataframe column that I would like to be formatted to two decimal places.

Such that:

10.1

Appears as:

10.10

How can I do that? I have already tried rounding.

Does this answer your question? [Add zeros to a float after the decimal point in Python](https://stackoverflow.com/questions/15619096/add-zeros-to-a-float-after-the-decimal-point-in-python) — iacob, Sep 30 '21 at 23:26

score 3 · Answer 1 · answered Mar 05 '20 at 17:56

3

This can be accomplished by mapping a string format object to the column of floats:

df.colName.map('{:.2f}'.format)

(Credit to exp1orer)

answered Mar 05 '20 at 17:56

johnDanger

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score 1 · Answer 2 · answered Nov 19 '19 at 15:55

1

You can use:

pd.options.display.float_format = '{:,.2f}'.format

Note that this will only display two decimals for every float in your dataframes.
To go back to normal:

pd.reset_option('display.float_format')

answered Nov 19 '19 at 15:55

Horace

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How would you do this for a single column? – David Nov 19 '19 at 16:08
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@David df.style.format({'col': "{:,.2f}"}) if 'col' is the name of your column. – Horace Mar 02 '20 at 13:14
This was perfect for displaying currency without displaying a symbol. This was particularly valuable when writing to an Excel file with Pandas. – BrianS Dec 03 '21 at 23:41

score 0 · Answer 3 · answered Nov 19 '19 at 15:57

From pyformat.info

Padding numbers

For floating points the padding value represents the length of the complete output. In the example below we want our output to have at least 6 characters with 2 after the decimal point.

'{:06.2f}'.format(3.141592653589793)

The :06 is the length of your output regardless of how many digits are in your input. The .2 indicates you want 2 places after the decimal point. The f indicates you want a float output.

Output

003.14

How would you do this for a whole column? – David Nov 19 '19 at 16:03 — David, Nov 19 '19 at 16:03

score -2 · Accepted Answer · answered Nov 19 '19 at 16:30

-2

If you are using Python 3.6 or later you can use f strings. Check out this other answer: https://stackoverflow.com/a/45310389/12229158

>>> a = 10.1234
>>> f'{a:.2f}'
'10.12'

answered Nov 19 '19 at 16:30

whege

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How do you do this for a whole column? – David Nov 19 '19 at 16:37
I think the most straightforward way is a list comprehensions, as suggested on another thread. This would be: df['b'] = [f'{a:.2f}' for a in df['column']]. This creates a new column but you could swap 'b' for the column of interest to overwrite, or drop the old column after creating this new one. – whege Nov 19 '19 at 16:57

How to add a trailing zeros to a pandas dataframe column?

4 Answers4