Say this is your number. a_number = 1234567890 You can add the commas like this print(format(a_number, ",")) or like this. print(f"{a_number:,}") Either way, what you're doing here is using a "format specifier" to create a string from the number formatted the way you like. A , means to format your integer or floating point number with commas every third numbers to the left of the decimal. You can see the full list of format specifiers here in the documentation (though TBH it's a bit hard to find what you need in it). Answer from Deleted User on reddit.com
Reddit
reddit.com › r/learnpython › how do i put commas between numbers?
r/learnpython on Reddit: How do I put commas between numbers?
October 24, 2021 -
Let's say I have 2792819, now I want it to be like 2,792,819. How do I do it?
I can do so while reversing it and after every 3 iterations, put a comma or something like that. But is there a better way to do so?
Top answer 1 of 3
19
Say this is your number. a_number = 1234567890 You can add the commas like this print(format(a_number, ",")) or like this. print(f"{a_number:,}") Either way, what you're doing here is using a "format specifier" to create a string from the number formatted the way you like. A , means to format your integer or floating point number with commas every third numbers to the left of the decimal. You can see the full list of format specifiers here in the documentation (though TBH it's a bit hard to find what you need in it).
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5
for any formatting question, pyformat is the place to be
GeeksforGeeks
geeksforgeeks.org › python › print-number-commas-1000-separators-python
Print number with commas as 1000 separators in Python - GeeksforGeeks
May 14, 2025 - Format the number and add commas as a thousand separators to use the ',d' formatting syntax in the format() function. ... F-string with replaces function. ... Here, we have used the "{:,}" along with the format() function to add commas every ...
string - How to format a number with comma every four digits in Python? - Stack Overflow
1309 How to print a number using commas as thousands separators · 98 How do I format a number with a variable number of digits in Python? More on stackoverflow.com
Can anyone help me with this problem?
Write a function named format_number that takes a non-negative number as its only parameter. Your function should convert the number to a string and add commas as a thousands separator. For example, calling format_number(1000000) should return "1,000,000". More on discuss.python.org
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November 19, 2022python - Add commas into number string - Stack Overflow
This is documented in PEP 378 -- ... the comma as a thousands separator" ... Sign up to request clarification or add additional context in comments. ... Likely the values would be floats, not integers, so it would be format(value, ",f") 2015-07-31T21:51:01.177Z+00:00 ... You could use locale.currency if TotalAmount represents money. It works on Python <2.7 ... More on stackoverflow.com
Format Integer With Comma Using Python Printf
I have built a slider that has integer values between, say, 0 and 2,000,000. I would like to display the numbers with thousands-commas-separator. The documentation states: format (str or None) – A printf-style format string controlling how the interface should display numbers. More on discuss.streamlit.io
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March 30, 2020Videos
01:27
Python: Print Numbers with Commas - YouTube
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Python F String Formatting Adding Commas to Numbers - YouTube
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Commas in Python integer input and output - YouTube
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Format Large Numbers with Commas in Python|Program-10|JNTUKR19...
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python format number with commas and 2 decimal places - YouTube
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Python 76: Formatting numbers as currency using the format() method ...
Top answer 1 of 16
2569
Locale-agnostic: use _ as the thousand separator
f'{value:_}' # For Python ≥3.6
Note that this will NOT format in the user's current locale and will always use _ as the thousand separator, so for example:
1234567 ⟶ 1_234_567
English style: use , as the thousand separator
'{:,}'.format(value) # For Python ≥2.7
f'{value:,}' # For Python ≥3.6
Locale-aware
import locale
locale.setlocale(locale.LC_ALL, '') # Use '' for auto, or force e.g. to 'en_US.UTF-8'
'{:n}'.format(value) # For Python ≥2.7
f'{value:n}' # For Python ≥3.6
Reference
Per Format Specification Mini-Language,
The
','option signals the use of a comma for a thousands separator. For a locale aware separator, use the'n'integer presentation type instead.
and:
The
'_'option signals the use of an underscore for a thousands separator for floating point presentation types and for integer presentation type'd'. For integer presentation types'b','o','x', and'X', underscores will be inserted every 4 digits.
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I'm surprised that no one has mentioned that you can do this with f-strings in Python 3.6+ as easy as this:
>>> num = 10000000
>>> print(f"{num:,}")
10,000,000
... where the part after the colon is the format specifier. The comma is the separator character you want, so f"{num:_}" uses underscores instead of a comma. Only "," and "_" is possible to use with this method.
This is equivalent of using format(num, ",") for older versions of python 3.
This might look like magic when you see it the first time, but it's not. It's just part of the language, and something that's commonly needed enough to have a shortcut available. To read more about it, have a look at the group subcomponent.
Alexwlchan
alexwlchan.net › notes › 2025 › python-comma-n
Print a comma-separated number in Python with {num:,} – alexwlchan
May 28, 2025 - You can use `{num:,}` to insert a comma every three digits, `{num:_}` to insert an underscore every three digits, and `{num:n}` to insert a locale-aware digit separator.
Top answer 1 of 4
7
Regex will work for you:
import re
def format_number(n):
return re.sub(r"(\d)(?=(\d{4})+(?!\d))", r"\1,", str(n))
>>> format_number(123)
'123'
>>> format_number(12345)
'1,2345'
>>> format_number(12345678)
'1234,5678'
>>> format_number(123456789)
'1,2345,6789'
Explanation:
Match:
(\d)Match a digit...(?=(\d{4})+(?!\d))...that is followed by one or more groups of exactly 4 digits.
Replace:
\1,Replace the matched digit with itself and a,
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Sounds like a locale thing(*). This prints 12,3456,7890 (Try it online!):
import locale
n = 1234567890
locale._override_localeconv["thousands_sep"] = ","
locale._override_localeconv["grouping"] = [4, 0]
print(locale.format_string('%d', n, grouping=True))
That's an I guess hackish way based on this answer. The other answer there talks about using babel, maybe that's a clean way to achieve it.
(*) Quick googling found this talking about Chinese grouping four digits, and OP's name seems somewhat Chinese, so...
Python.org
discuss.python.org › python help
Can anyone help me with this problem? - Python Help - Discussions on Python.org
November 19, 2022 - Write a function named format_number that takes a non-negative number as its only parameter. Your function should convert the number to a string and add commas as a thousands separator.
Top answer 1 of 11
160
In Python 2.7 and 3.x, you can use the format syntax :,
>>> total_amount = 10000
>>> print("{:,}".format(total_amount))
10,000
>>> print("Total cost is: ${:,.2f}".format(total_amount))
Total cost is: $10,000.00
This is documented in PEP 378 -- Format Specifier for Thousands Separator and has an example in the Official Docs "Using the comma as a thousands separator"
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38
if you are using Python 3 or above, here is an easier way to insert a comma:
First way
value = -12345672
print (format (value, ',d'))
or another way
value = -12345672
print ('{:,}'.format(value))
AskPython
askpython.com › home › adding commas into number string
Adding commas into number string - AskPython
February 27, 2023 - Adding commas to an integer string ... several built-in methods can be used to achieve this goal, such as the format() function and the locale module. These methods can format numbers ......
GeeksforGeeks
geeksforgeeks.org › python › python-add-comma-between-numbers
Add Comma Between Numbers - Python - GeeksforGeeks
July 12, 2025 - format() function in Python provides a simple and efficient way to add commas between numbers. ... The :, within the curly braces tells Python to insert commas as a thousand separator.
Streamlit
discuss.streamlit.io › using streamlit
Format Integer With Comma Using Python Printf - Using Streamlit - Streamlit
March 30, 2020 - I have built a slider that has integer values between, say, 0 and 2,000,000. I would like to display the numbers with thousands-commas-separator. The documentation states: format (str or None) – A printf-style format st…
Invent with Python
inventwithpython.com › pythongently › exercise33
Exercise 33 - Comma-Formatted Numbers
We need to loop starting at the one’s place in the number and moving left, so our for loop should work in reverse: for i in range(len(number) - 1, -1, -1). For example, if number is 4096, then the first iteration of the loop can access number[3], the second iteration can access number[2], ...
Python
peps.python.org › pep-0378
PEP 378 – Format Specifier for Thousands Separator | peps.python.org
March 12, 2009 - The proposal works well with floats, ints, and decimals. It also allows easy substitution for other separators. For example: ... This technique is completely general but it is awkward in the one case where the commas and periods need to be swapped: format(n, "6,f").replace(",", "X").replace(".", ",").replace("X", ".")
Seqera Community
community.seqera.io › ask for help
Number formatting "comma" doesn't seem to work - Ask for help - Seqera Community
January 16, 2024 - I’m trying to use the hint regarding numerical formatting that is provided here, understanding this as python-style format string. However, I’m unable to cause the formatting to use comma (,) as the thousands separator (underscore works…) Here’s a simple example: custom_data: test: plot_type: "table" headers: value: format: "{:,.2f}" sp: test: fn: "hello.txt" and hello.txt contains: sample value test 100000.55555 The resulting html has the following: i.e. t...
Top answer 1 of 2
9
Your own example is able to do what you want. Just write it properly without mixing format styles:
a = 1234567
print "The number is {:,d} but it's converted to a string".format(a)
That's a good reason to use the modern syntax. It does not care about the type of the argument. It will use str on the object and output it accordingly.
print "The number is {:,d} and John has {} sisters and {} brothers".format(1000000, 2, 3)
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To be clear, a itself is not being changed into a string. There is a temporary, anonymous string object created by '{:,d}'.format(a) and then fed to "%s" %:
>>> a = 1234567
>>> "The number is %s but it's converted to a string" %'{:,d}'.format(a)
"The number is 1,234,567 but it's converted to a string"
>>> type(a)
<type 'int'>
>>> a
1234567
So a itself has not changed at all similarly as your second example does not change the object b:
>>> b = 0.1234
>>> "The Norwegian Blue prefers kippin' on it's back! %0.2f%%" % (b*100)
"The Norwegian Blue prefers kippin' on it's back! 12.34%"
>>> type(b)
<type 'float'>
>>> b
0.1234
So the underlying values of a and b are not changing. The issue is that you are using a less than clear syntax to print a. Just do:
>>> "The number is {:,d} but it's NOT converted to a string".format(a)
"The number is 1,234,567 but it's NOT converted to a string"
There is no need to do two formatting steps as you have in your example.
Littlecolumns
littlecolumns.com › learn › python › f-strings
Formatting output with f strings - Python's Not (Just) For Unicorns
We learned about f strings, which are a nicer way to print and format strings. They work like fill-in-the-blanks with our variables, and all you need to do is add a f at the beginning of the string! F-strings also let us do fun tricks like rounding and adding commas if we have long decimals or large numbers. Next up: Project - Moon Measurer with Dictionaries · Hi, I'm Soma. I'm writing PNJ4U because bad tutorials make me grumpy. You think it's your fault you can't code? No way, friend, Python's not (just) for unicorns!
AskPython
askpython.com › home › how to print a number using commas as separators?
How to print a number using commas as separators? - AskPython
March 31, 2023 - The curly braces contain data that we want to replace the string. Let’s see the example of using an f-string as a commas separator. ... Here, the ‘Number’ is assigned with the integer value.
TutorialsPoint
tutorialspoint.com › article › print-number-with-commas-as-1000-separators-in-python
Print number with commas as 1000 separators in Python
2 weeks ago - # Format floats with commas and 2 decimal places price1 = 3435.242563 price2 = 1234567.89 price3 = 999.5 print(f'{price1:,.2f}') print(f'{price2:,.2f}') print(f'{price3:,.2f}') ... # Using format() method num = 2500000 price = 12345.678 ...
Codemia
codemia.io › knowledge-hub › path › how_to_print_a_number_using_commas_as_thousands_separators
How to print a number using commas as thousands ...
Enhance your system design skills with over 120 practice problems, detailed solutions, and hands-on exercises.
Mark Needham
markhneedham.com › blog › 2021 › 04 › 11 › pandas-format-dataframe-numbers-commas-decimals
Pandas - Format DataFrame numbers with commas and control decimal places | Mark Needham
April 11, 2021 - That doesn’t work because the LTLA Name column contains string values, which can’t be formatted as a number. We can work around that problem by dropping the LTLA Name column: df.drop(["LTLA Name"], axis=1).style.format("{:.2f}") This works, but we’ve lost the LTLA Name column and the Population column isn’t formatted how we’d like. Instead of passing a single style to style.format, we can instead pass a dictionary of {"column: "style"}. So to style Population with a comma as thousands separator and PercentageVaccinated with two decimal places, we can do the following:
Bobby Hadz
bobbyhadz.com › blog › python-format-number-thousands-separator-2-decimals
Format number with comma as thousands separator in Python | bobbyhadz
April 9, 2024 - As noted in the docs, the , option signals the use of a comma for a thousands separator. The n integer presentation type is used for a locale-aware separator. You can also use the str.format() method to format a number with a comma as the thousands ...