Print format decimal python

String Formatting

Python v2.7 introduced a new string formatting method, that is now the default in Python3. I started this string formatting cookbook as a quick reference to help me format numbers and strings. Thanks to other contributors I’ve expanded the examples over time.

Python 3.6 introduced, formatted string literals, often referred to as f-strings as another method to help format strings. It is simpler to prepend an f to the string then append .format() . Using f-strings in Python is similar to JavaScript’s template literals, if you are familiar with them.

Here’s an example comparing the three ways to format a float number:

pi = 3.14159 print(" pi = %1.2f " % pi) # older print(" pi = ".format( pi )) # .format() print(f" pi = pi:.2f>") # f-string 

Number formatting

This table shows various ways to format numbers using Python’s str.format() and formatted string literals, including examples for both float formatting and integer formatting.

To run examples use: print(f»») or print(«».format(NUM));

Number	Format	Output	Description
3.1415926		3.14	Format float 2 decimal places
3.1415926		+3.14	Format float 2 decimal places with sign
-1		-1.00	Format float 2 decimal places with sign
2.71828		3	Format float with no decimal places
5	2d>	05	Pad number with zeros (left padding, width 2)
5		5xxx	Pad number with x’s (right padding, width 4)
1000000		1,000,000	Number format with comma separator
0.25		25.00%	Format percentage
1000000000		1.00e+09	Exponent notation
13		13	Right aligned (default, width 10)
13		13	Left aligned (width 10)
13		13	Center aligned (width 10)

String .format() basics

Here are a couple of examples of basic string substitution, the <> is the placeholder for substituted variables. If no format is specified, it will insert and format as a string.

s1 = "show me the <>".format("money") s2 = "hmmm, this is a <> <>".format("tasty", "burger") 

With formatted string literals, this is simply:

s1 = f"show me the money>" s2 = f"hmmm, this is a tasty> burger>" 

Substitution positioning

One benefit of .format() that is not available in f-strings is using the numeric position of the variables and change them in the strings, this gives some flexibility when doing the formatting, if you make a mistake in the order you can easily correct without shuffling all the variables around.

s1 = "  is better than  ".format("emacs", "vim") s2 = "  is better than  ".format("emacs", "vim") 

Variable formatting

You can use <> as a variable inside the formatting brackets (h/t Peter Beens for tip). This example uses a precision variable to control how many decimal places to show:

pi = 3.1415926 precision = 4 print( "<>f>".format( pi, precision ) ) >>> 3.1415 

Older % string formatter

An example comparing variable substitution with the older % method vs. .format() :

s1 = "cats" s2 = "dogs" s3 = " %s and %s living together" % (s1, s2) s4 = " <> and <> living together ".format(s1, s2) 

Using the older format method, I would often get the errors:

TypeError: not enough arguments for format string 

TypeError: not all arguments converted during string formatting 

because I miscounted my substitution variables, doing something like the following made it easy to miss a variable.

Using one of the new Python string formatters you can use numbered parameters so you don’t have to count how many you have, at least on half of it.

set = " ( , , , , , , , ) ".format(a,b,c,d,e,f,g) 

Formatted string literals

As shown above, formatted string literals, or f-strings, use a shorter syntax making it easier and more template-like. F-strings also support functions inside of the brackets < >this allows you to:

Do math with f-strings:

print( f"Do math: 3 * 6 = 3 * 6>" ) >>> Do math: 3 * 6 = 18 

Call functions with f-strings;

verb = "runs" print( f"The girl verb.upper()> quickly." ) >>> The girl RUNS quickly. 

Delimiting f-strings

You can use f-strings using the three different type of quotation marks in Python, single, double, or triple quotes. The following will all output the same:

name = "Fred" print( f'name>' ) print( f"name>" ) print( f"""name>""" ) 

F-String error

The one thing you’ll want to be careful is mixing the two formats, if you try to use <> inside of an f-string, you will get the error:

SyntaxError: f-string: empty expression not allowed 

Each set of brackets used in an f-string requires a value or variable.

Formatting tips with .format()

The format() function offers additional features and capabilities, here are a few useful tips and tricks to format strings in Python:

Reuse same variable multiple times

Using % to format requires a strict ordering of variables, the .format() method allows you to put them in any order as well as repeating for reuse.

"Oh , ! wherefore art thou ?".format("Romeo") >>> 'Oh Romeo, Romeo! wherefore art thou Romeo?' 

Convert values to different bases

A surprising use, you can use the string format command to convert numbers to different bases. Use the letter in the formatter to indicate the number base: decimal, hex, octal, or binary.

This example formats the number 21 in each base:

"  -  -  -  ".format(21) >>> 21 - 15 - 25 - 10101 

Use format as a function

You can use .format as a function to separate text and formatting from code. For example, at the beginning of your program include all your formats for later use.

## defining formats email_f = "Your email address was ".format ## use elsewhere print(email_f(email="bob@example.com")) 

Hat tip to earthboundkids who provided this on reddit.

Using format as a function can be used to adjust formating by user preference.

## set user preferred format num_format = " ".format ## use elsewhere print(num_format(1000000)) 

Internationalization

To use locale specific formatting for numbers, you need to first set the locale, and then use the formating code n instead of d . For example, using commas or periods to separate thousands in numbers based on the user’s locale.

Here is an example, setting locale and formatting a number to display the proper separator:

import locale locale.setlocale(locale.LC_ALL, '') print(" ".format(1000000)) 

Escaping braces

If you need to use braces when using str.format() just double them up:

print(" The <> set is often represented as % raw %>>% endraw %>".format("empty")) ~~ The empty set is often represented as 0> 

Table formatting data

Use the width and the left and right justification to align your data into a nice table format. Here’s an example to show how to format:

# data starters = [ [ 'Andre Iguodala', 4, 3, 7 ], [ 'Klay Thompson', 5, 0, 21 ], [ 'Stephen Curry', 5, 8, 36 ], [ 'Draymon Green', 9, 4, 11 ], [ 'Andrew Bogut', 3, 0, 2 ], ] # define format row row = "|  |  |  |  |".format for p in starters: print(row(player=p[0], reb=p[1], ast=p[2], pts=p[3])) 

 | Andre Iguodala | 4 | 3 | 7 | | Klay Thompson | 5 | 0 | 21 | | Stephen Curry | 5 | 8 | 36 | | Draymon Green | 9 | 4 | 11 | | Andrew Bogut | 3 | 0 | 2 | 

Resources

• Python String Library – Standard Library Documentation
• My Python Argparse Cookbook – examples parsing command-line arguments
• My Python Date Formatting — examples working with Python dates.

Источник

Python print 2 decimal places [%.2f in Python]

In this Python tutorial, we will discuss on how to print 2 decimal places in Python.

• Python print 2 decimal places
• Python float precision truncate
• Python float precision ceil
• Python float precision floor
• Python decimal format
• Python round numbers
• Limiting floats to two decimal points

Python print 2 decimal places

In Python, to print 2 decimal places we will use str.format() with “” as string and float as a number. Call print and it will print the float with 2 decimal places.

float = 2.154327 format_float = "".format(float) print(format_float)

After writing the above code (python print 2 decimal places), Ones you will print “ format_float ” then the output will appear as a “ 2.15 ”. Here, it will format the float with 2 decimal places.

You can refer to the below screenshot python print 2 decimal places.

Python float precision truncate

Firstly, we need to import math module. Then the trunc() function is used to remove all decimal parts from the floating-point numbers and it returns only the integer part of the number.

import math float = 12.16785 print("The value of number is: ",end="") print (math.trunc(float))

After writing the above code (python float precision truncate), Ones you will print “ math.trunc(float)” then the output will appear as a “ The value of a number is: 12 ”. Here, trunc() will print integer value after truncating.

You can refer to the below screenshot for python float precision truncate

Python float precision ceil

In Python, the ceil() function is used to return the ceiling value of a number. The ceil value is the smallest integer greater than the number.

import math float = 12.16785 print("The smallest integer greater than number is: ",end="") print (math.ceil(float))

After writing the above code (python float precision ceil), Ones you will print “ math.ceil(float) ” then the output will appear as a “ The smallest integer greater than a number is: 13 ”. Here, we used ceil to print numbers after the ceiling. It will return the smallest integer greater than the given number.

You can refer to the below screenshot for python float precision ceil.

Python float precision floor

Python floor() function is used to return the floor value of a number. The floor value is the greatest integer smaller than the number.

import math float = 12.16785 print("The greatest integer smaller than number is: ",end="") print (math.floor(float))

After writing the above code (python float precision floor), Ones you will print “math.floor(float)” then the output will appear as a “ The greatest integer smaller than a number is: 12 ”. Here, we used the floor to print numbers after flooring. It will return the greatest integer smaller than the number.

You can refer to the below screenshot for python float precision floor.

Python decimal format

To format decimals, we will use str.format(number) where a string is ‘’ and it will format string with a number. Also, it will display the number with 1 number before the decimal and up to 2 numbers after the decimal.

number = 1.345 f = ''.format(number) print(f)

After writing the above code (python decimal format), Ones you will print “ f ” then the output will appear as a “ 1.34 ”. Here, formatting decimals displays numbers with a certain number after the decimal point.

You can refer to the below screenshot for python decimal format.

Python round numbers

To round numbers in python, we will use the round() function. The round function will round off a number to a given number of digits and makes rounding of numbers easier.

number = 1.345 print(round(number))

After writing the above code (python round numbers), Ones you will print “ number ” then the output will appear as a “ 1 ”. Here, the number 1.345 float number will be rounded to 1.

You can refer to the below screenshot for python round numbers.

Limiting floats to two decimal points

The round() function returns a floating-point number which will be rounded to specified numbers, and it will round the float to two decimal places.

my_float = 2.13456 limit_float = round(my_float, 2) print(limit_float)

After writing the above code (limiting floats to two decimal points), Ones you will print “limit_float” then the output will appear as a “ 2.13 ”. Here, the round(number) with a float number and 2 as ndigits to round float to two decimal points.

You can refer to the below screenshot for python round numbers.

You may like the following Python tutorials:

In this tutorial, we learned how to print 2 decimal places in python and also we covered the below topics:

• Python print 2 decimal places
• Python float precision truncate
• Python float precision ceil
• Python float precision floor
• Python decimal format
• Python round numbers
• Limiting floats to two decimal points

I am Bijay Kumar, a Microsoft MVP in SharePoint. Apart from SharePoint, I started working on Python, Machine learning, and artificial intelligence for the last 5 years. During this time I got expertise in various Python libraries also like Tkinter, Pandas, NumPy, Turtle, Django, Matplotlib, Tensorflow, Scipy, Scikit-Learn, etc… for various clients in the United States, Canada, the United Kingdom, Australia, New Zealand, etc. Check out my profile.

Источник