# How to suppress scientific notation when printing float values?

## Question:

Here’s my code:

```
x = 1.0
y = 100000.0
print x/y
```

My quotient displays as `1.00000e-05`

.

Is there any way to suppress scientific notation and make it display as

`0.00001`

? I’m going to use the result as a string.

## Answers:

```
'%f' % (x/y)
```

but you need to manage precision yourself. e.g.,

```
'%f' % (1/10**8)
```

will display zeros only.

details are in the docs

Or for Python 3 the equivalent old formatting or the newer style formatting

In addition to SG’s answer, you can also use the Decimal module:

```
from decimal import Decimal
x = str(Decimal(1) / Decimal(10000))
# x is a string '0.0001'
```

With newer versions of Python (2.6 and later), you can use `''.format()`

to accomplish what @SilentGhost suggested:

```
'{0:f}'.format(x/y)
```

If it is a `string`

then use the built in `float`

on it to do the conversion for instance:

`print( "%.5f" % float("1.43572e-03"))`

answer:`0.00143572`

Using the newer version `''.format`

(also remember to specify how many digit after the `.`

you wish to display, this depends on how small is the floating number). See this example:

```
>>> a = -7.1855143557448603e-17
>>> '{:f}'.format(a)
'-0.000000'
```

as shown above, default is 6 digits! This is not helpful for our case example, so instead we could use something like this:

```
>>> '{:.20f}'.format(a)
'-0.00000000000000007186'
```

## Update

Starting in Python 3.6, this can be simplified with the new formatted string literal, as follows:

```
>>> f'{a:.20f}'
'-0.00000000000000007186'
```

This will work for any exponent:

```
def getExpandedScientificNotation(flt):
str_vals = str(flt).split('e')
coef = float(str_vals[0])
exp = int(str_vals[1])
return_val = ''
if int(exp) > 0:
return_val += str(coef).replace('.', '')
return_val += ''.join(['0' for _ in range(0, abs(exp - len(str(coef).split('.')[1])))])
elif int(exp) < 0:
return_val += '0.'
return_val += ''.join(['0' for _ in range(0, abs(exp) - 1)])
return_val += str(coef).replace('.', '')
return return_val
```

This is using Captain Cucumber’s answer, but with 2 additions.

1) allowing the function to get non scientific notation numbers and just return them as is (so you can throw a lot of input that some of the numbers are 0.00003123 vs 3.123e-05 and still have function work.

2) added support for negative numbers. (in original function, a negative number would end up like 0.0000-108904 from -1.08904e-05)

```
def getExpandedScientificNotation(flt):
was_neg = False
if not ("e" in flt):
return flt
if flt.startswith('-'):
flt = flt[1:]
was_neg = True
str_vals = str(flt).split('e')
coef = float(str_vals[0])
exp = int(str_vals[1])
return_val = ''
if int(exp) > 0:
return_val += str(coef).replace('.', '')
return_val += ''.join(['0' for _ in range(0, abs(exp - len(str(coef).split('.')[1])))])
elif int(exp) < 0:
return_val += '0.'
return_val += ''.join(['0' for _ in range(0, abs(exp) - 1)])
return_val += str(coef).replace('.', '')
if was_neg:
return_val='-'+return_val
return return_val
```

Using 3.6.4, I was having a similar problem that randomly, a number in the output file would be formatted with scientific notation when using this:

```
fout.write('someFloats: {0:0.8},{1:0.8},{2:0.8}'.format(someFloat[0], someFloat[1], someFloat[2]))
```

All that I had to do to fix it was to add ‘f’:

```
fout.write('someFloats: {0:0.8f},{1:0.8f},{2:0.8f}'.format(someFloat[0], someFloat[1], someFloat[2]))
```

Since this is the top result on Google, I will post here after failing to find a solution for my problem. **If you are looking to format the display value of a float object and have it remain a float – not a string, you can use this solution:**

Create a new class that modifies the way that float values are displayed.

```
from builtins import float
class FormattedFloat(float):
def __str__(self):
return "{:.10f}".format(self).rstrip('0')
```

You can modify the precision yourself by changing the integer values in `{:f}`

Another option, if you are using pandas and would like to suppress scientific notation for all floats, is to adjust the pandas options.

```
import pandas as pd
pd.options.display.float_format = '{:.2f}'.format
```

As of 3.6 (probably works with slightly older 3.x as well), this is my solution:

```
import locale
locale.setlocale(locale.LC_ALL, '')
def number_format(n, dec_precision=4):
precision = len(str(round(n))) + dec_precision
return format(float(n), f'.{precision}n')
```

The purpose of the `precision`

calculation is to ensure we have enough precision to keep out of scientific notation (default precision is still 6).

The `dec_precision`

argument adds additional precision to use for decimal points. Since this makes use of the `n`

format, no insignificant zeros will be added (unlike `f`

formats). `n`

also will take care of rendering already-round integers without a decimal.

`n`

does require `float`

input, thus the cast.

Most of the answers above require you to specify precision. But what if you want to display floats like this, with no unnecessary zeros:

```
1
0.1
0.01
0.001
0.0001
0.00001
0.000001
0.000000000001
```

`numpy`

has an answer: `np.format_float_positional`

```
import numpy as np
def format_float(num):
return np.format_float_positional(num, trim='-')
```

A simpler solution to display a float to an arbitrary number of significant digits. No `numpy`

or list comprehensions required here:

```
def sig(num, digits=3):
"Return number formatted for significant digits"
if num == 0:
return 0
negative = '-' if num < 0 else ''
num = abs(float(num))
power = math.log(num, 10)
if num < 1:
step = int(10**(-int(power) + digits) * num)
return negative + '0.' + '0' * -int(power) + str(int(step)).rstrip('0')
elif power < digits - 1:
return negative + ('{0:.' + str(digits) + 'g}').format(num)
else:
return negative + str(int(num))
```

I’m stripping trailing 0s and displaying full integers in the example: `sig(31415.9) = 31415`

instead of 31400. Feel free to modify the code if that’s not something you’re into.

Testing:

```
for power in range(-8,8):
num = math.pi * 10**power
print(str(num).ljust(25), sig(num))
```

You can use the built-in `format`

function.

```
>>> a = -3.42142141234123e-15
>>> format(a, 'f')
'-0.000000'
>>> format(a, '.50f') # Or you can specify precision
'-0.00000000000000342142141234122994048466990874926279'
```

In case of numpy arrays you can suppress with suppress command as

```
import numpy as np
np.set_printoptions(suppress=True)
```

I was having a similar problem that randomly, using my solution:

```
from decimal import Decimal
Decimal(2/25500)
#output:0.00007843137254901961000728982664753630160703323781490325927734375
```