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October 28, 2022
Python Strings Format () And Types
mrexamples.com/python/references/python-strings-format
Python Strings Format Methods And Types
We will explain Python strings format and its types in this chapter with examples to
meet your learning objectives.
Python Strings Format
Python Strings Format – Definition and Usage
Using curly brackets, we define the placeholder: {}. In the Placeholder section below, you
can learn more about the placeholders.
Strings and numbers cannot be combined like this in Python Variables:
What Is The Format Of a String In Python?
When we talk about Python strings format then in Python, a string is a sequence of
characters enclosed in either single quotes (‘ ‘) or double quotes (” “). The choice
between single or double quotes is up to the programmer, and both are used
interchangeably.
Here are a few examples of string literals in Python:
name = ‘John’ message = “Hello, world!” sentence = “I’m learning Python.”

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Python also supports triple quotes (”’ ”’) or (“”” “””) to represent multiline strings. Triple
quotes allow you to include line breaks and preserve the formatting of the text. Here’s an
example:
paragraph = ”’This is a multiline string. It spans multiple lines and preserves the line
breaks and formatting.”’
In addition to the basic string literals, Python provides various string manipulation
methods and features that allow you to work with strings efficiently.
What Is .2f Python Format?
In Python, the .2f format specifier is used to format floating-point numbers as strings with
two decimal places. This format specifier is part of the Python strings format syntax in
Python.
When using the .2f format specifier, the number will be rounded to two decimal places
and displayed with two digits after the decimal point. If the number has fewer than two
decimal places, it will be padded with zeros.
Here’s an example that demonstrates the usage of the .2f format specifier:
number = 3.14159 formatted_number = “{:.2f}”.format(number) print(formatted_number)
Output:
3.14
In this example, the variable number contains the value 3.14159. By applying the .2f
format specifier within the format() method and using the “{:.2f}” format string, the number
is formatted to have two decimal places. The resulting formatted number is then printed,
which outputs 3.14.
You can also achieve the same result using f-strings, which is a more concise and
preferred way of string formatting in Python 3.6 and above:
number = 3.14159 formatted_number = f”{number:.2f}” print(formatted_number)
The output will be the same as before: 3.14.
What Is %d In String Format?
In Python, the %d format specifier is used to format integers as strings within the context
of the old-style string formatting method. It allows you to insert integer values into a string
when it comes to Python strings format.
Here’s an example that demonstrates the usage of %d in string formatting:
age = 25 message = “I am %d years old.” % age print(message)

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Output:
I am 25 years old.
In this example, the integer value age is inserted into the string using %d. The % operator
is used to combine the format string with the value to be formatted. The resulting string is
then printed.
Note that the %d format specifier only works with integers. If you try to use it with a non-
integer value, you will encounter a TypeError.
It’s worth mentioning that the old-style string formatting method using % is considered
legacy and has been replaced by more modern string formatting options, such as the
.format() method or f-strings. These newer methods provide more flexibility and
readability. Here’s an equivalent example using f-strings:
age = 25 message = f”I am {age} years old.” print(message)
The output will be the same: I am 25 years old.
What Does %% s Mean In Python?
In Python, %%s is not a valid format specifier or syntax. It appears to be an incorrect use
of string formatting.
In Python, the standard format specifier for inserting a string into a formatted string is %s.
The %s format specifier is used to represent a placeholder for a string value as it comes
to Python strings format.
Here’s an example of using %s to format a string:
name = “Alice” message = “Hello, %s!” % name print(message)
Output:
Hello, Alice!
In this example, %s is used as a placeholder in the format string. The value of the
variable name is inserted into the string using the % operator and %s format specifier.
If you encountered %%s in code, it may be a typo or an error. Double percent (%%) is
used as an escape sequence to represent a literal percent sign in string formatting. For
example, “%%s” would be used to print the string “%s” as a literal string, without any
value substitution in Python strings format.
What Is ___ str __ In Python?

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When we discuss Python strings format, then in Python, __str__ is a special method
that you can define within a class to provide a string representation of an object. It is
invoked when you use the str() function or the print() function on an instance of the class.
When you define the __str__ method in a class, you can customize the string
representation of objects of that class to provide meaningful information. This method
should return a string that represents the object.
Here’s an example that demonstrates the usage of __str__:
class Person: def __init__(self, name, age): self.name = name self.age = age def
__str__(self): return f”Person(name='{self.name}’, age={self.age})” person =
Person(“Alice”, 25) print(person)
Output:
Person(name=’Alice’, age=25)
In this example, the Person class defines the __str__ method. The method returns a
formatted string representation of the object, including the name and age attributes.
When the print() function is called with an instance of the Person class, the __str__
method is automatically invoked to provide the string representation of the object as it
comes to Python strings format.
By defining the __str__ method, you can control how your objects are displayed as
strings, making it easier to understand and debug your code.
What Does S+ S+ Mean In Python?
In Python, the pattern s+ is a regular expression pattern that matches one or more
whitespace characters.
Let’s break down the pattern:
is an escape sequence that represents a single backslash character . In regular
expressions, a backslash is used to escape special characters and give them their
literal meaning.
s is a special character in regular expressions that represents any whitespace
character, such as spaces, tabs, or line breaks.
+ is a quantifier in regular expressions that specifies that the preceding pattern (in
this case, s) should match one or more times consecutively.
When combined, s+ matches one or more whitespace characters.
Here’s an example that demonstrates the usage of this pattern:
import re text = “Hello world” matches = re.findall(r”s+”, text) print(matches)
Output:

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[‘ ‘]
In this example, the re.findall() function is used to find all occurrences of one or more
whitespace characters in the text string. The regular expression pattern r”s+” is passed
as the first argument to re.findall(). As a result, it returns a list containing the match found,
which is the sequence of spaces in the string.
Regular expressions are powerful tools for pattern matching and text manipulation. They
provide a concise way to specify complex patterns and search for matches within strings.
The re module in Python provides various functions and methods for working with
regular expressions as it comes to Python strings format.
What Does ___ Mean In Python?
In Python, the underscores (___) can have different meanings depending on their context.
Let’s explore a few common use cases:
Placeholder Variables:
Underscores are often used as placeholder variables when you don’t intend to use the
value. It is a convention to use a single underscore (_) or multiple underscores (__, ___,
etc.) for such variables. For example:
for _ in range(5): print(“Hello”)
In this case, the loop variable _ is used as a placeholder. It indicates that the loop variable
is not going to be used within the loop body.
Name Mangling:
Double underscores (__) at the beginning of an identifier trigger name mangling in class
definitions. It is used to make a class attribute “private” or to avoid naming conflicts in
subclasses. For example:
class MyClass: def __init__(self): self.__private_variable = 42 def __private_method(self):
print(“This is a private method.”) obj = MyClass() print(obj._MyClass__private_variable)
obj._MyClass__private_method()
Here, the double underscores in __private_variable and __private_method cause name
mangling. The actual attribute names become _MyClass__private_variable and
_MyClass__private_method. Although not truly private, it is a way to discourage
accessing these attributes directly from outside the class.
Special Methods:
Double underscores are used to denote special methods in Python classes. These
methods have a specific purpose and are invoked implicitly in certain situations.
Examples include __init__ (constructor), __str__ (string representation), __len__ (length),
and many more.

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class MyClass: def __init__(self, value): self.value = value def __str__(self): return
f”MyClass instance with value: {self.value}” obj = MyClass(42) print(obj) # Invokes __str__
method implicitly
In this example, the __init__ method is the constructor, and the __str__ method is
invoked implicitly when the print() function is called on an instance of MyClass.
Underscores have different meanings depending on their usage, so it’s essential to
understand the context in which they are used to interpret their purpose correctly as it
comes to Python strings format.
What Is %s vs d In Python?
In Python, %s and %d are format specifiers used in string formatting to insert values into
a formatted string. However, they are used for different types of data:
%s: The %s format specifier is used to represent a placeholder for a string value. It can
be used to insert any type of data into a string, as it will automatically convert the value to
its string representation. For example:
name = “Alice” age = 25 message = “My name is %s and I am %s years old.” % (name,
age) print(message)
Output:
My name is Alice and I am 25 years old.
In this example, %s is used to insert the values of name and age into the string message.
%d: The %d format specifier is specifically used for inserting integer values into a
formatted string. It is not suitable for inserting strings or other data types. For example:
quantity = 5 price = 10.5 total = quantity * price message = “The total cost is %d.” % total
print(message)
Output:
The total cost is 52.
In this example, %d is used to insert the value of total (which is an integer) into the string
message.
It’s important to note that the old-style string formatting using % and format specifiers
(%s, %d, etc.) is considered legacy and has been replaced by more modern string
formatting options, such as the .format() method and f-strings. These newer methods
provide more flexibility and readability. Here’s an equivalent example using f-strings:
name = “Alice” age = 25 message = f”My name is {name} and I am {age} years old.”
print(message)

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The output will be the same: My name is Alice and I am 25 years old.
What Does ‘% d Mean In Python?
In Python, ‘% d’ is a format specifier used in string formatting to represent a placeholder
for an integer value with optional space padding for positive numbers.
The format specifier ‘% d’ consists of the percent sign (%) followed by a space and the
letter d.
Here’s an example that demonstrates the usage of ‘% d’:
number = 42 formatted_number = ‘% d’ % number print(formatted_number)
Output:
42
In this example, the integer value number is inserted into the formatted string using ‘% d’.
The space before d indicates that positive numbers should be padded with a space
character. Negative numbers will still be displayed with a leading minus sign.
If the number is positive, it will be preceded by a space character to align it with the
negative numbers. If the number is negative, it will be displayed with a leading minus sign
as usual.
Note that the ‘% d’ format specifier can also accept width and precision specifications,
similar to other format specifiers. For example, ‘% 5d’ will pad positive numbers with
spaces to a width of 5 characters.
It’s worth mentioning that the old-style string formatting using % and format specifiers (‘%
d’, %s, etc.) is considered legacy and has been replaced by more modern string
formatting options, such as the .format() method and f-strings. These newer methods
provide more flexibility and readability. Here’s an equivalent example using f-strings:
number = 42 formatted_number = f'{number: d}’ print(formatted_number)
The output will be the same: 42.
What Is %R In Python?
In Python, %R is not a standard format specifier for string formatting. There is no built-in
format specifier %R in Python’s string formatting syntax.
If you encountered %R in code, it might be a custom format specifier defined by a specific
library or framework that extends Python’s string formatting capabilities. The meaning and
behavior of %R would depend on the context in which it is used and the specific library or
framework being used.

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To provide a more accurate answer, please provide more context or details about where
%R is used or the specific library or framework you are referring to.
What Does %C Do In Python?
In Python, %C is not a valid format specifier in the standard string formatting syntax.
There is no built-in format specifier %C in Python’s string formatting.
If you encountered %C in code, it might be a custom format specifier defined by a specific
library or framework that extends Python’s string formatting capabilities. The meaning and
behavior of %C would depend on the context in which it is used and the specific library or
framework being used.
To provide a more accurate answer, please provide more context or details about where
%C is used or the specific library or framework you are referring to.
Python Strings Format Float
In Python, you can format a float value as a string using various methods. Here are a few
commonly used approaches:
Using the format() method:
The format() method allows you to format a float value by specifying a format specifier
within curly braces {}. The format specifier for floats is f. You can specify the desired
number of decimal places using .n, where n represents the number of decimal places.
number = 3.14159 formatted_number = “{:.2f}”.format(number) print(formatted_number)
Output:
3.14
In this example, the format() method is used with the format string “{:.2f}” to format the
number with two decimal places. The resulting formatted number is then printed.
Using f-strings:
F-strings provide a concise and more readable way to format strings in Python 3.6 and
above. You can prefix the string with f and directly embed the float value within curly
braces {}. Similar to the format() method, you can specify the desired number of decimal
places using :.n.
Number = 3.14159 formatted_number = f”{number:.2f}” print(formatted_number)
The output will be the same: 3.14.
Using the % operator:

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The % operator can be used for string formatting in Python, known as the old-style string
formatting. For floats, the format specifier %f is used, followed by the desired number of
decimal places using .n.
number = 3.14159 formatted_number = “%.2f” % number print(formatted_number)
The output will be the same: 3.14.
These are a few common methods to format a float as a string in Python. Choose the one
that suits your preference and the requirements of your code.
Python Strings Format f
In Python, the f format specifier, also known as f-string or formatted string literal, allows
you to easily format strings by embedding expressions directly within curly braces {}. The
expressions are evaluated and their values are inserted into the string.
Here’s an example of using f-strings to format strings in Python:
name = “Alice” age = 25 formatted_string = f”My name is {name} and I am {age} years
old.” print(formatted_string)
Output:
My name is Alice and I am 25 years old.
In this example, the variables name and age are directly embedded within the string using
f-string syntax. The expressions {name} and {age} are evaluated and their values are
inserted into the string when it is printed.
F-strings provide a concise and readable way to format strings, as they allow you to
include expressions directly within the string declaration. You can also apply formatting
options to the expressions within the curly braces. For example, you can specify the
number of decimal places for a float value or control the width of an integer.
Here’s an example demonstrating additional formatting options using f-strings:
pi = 3.14159 formatted_number = f”The value of pi is approximately {pi:.2f}”
print(formatted_number)
Output:
The value of pi is approximately 3.14
In this example, the expression {pi:.2f} formats the value of pi as a float with two decimal
places.
F-strings offer a powerful and flexible way to format strings in Python, allowing you to
easily incorporate variables and expressions directly within your string declarations.

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Python f-String Format
In Python, f-strings (formatted string literals) provide a concise and convenient way to
format strings. With f-strings, you can embed expressions and variables directly within
curly braces {}.
To format values within f-strings, you can apply various formatting options. Here are some
common formatting options you can use within f-strings:
Specifying Width and Alignment:
You can specify the width and alignment of the formatted value by adding a colon :
followed by a format specification. For example:
name = “Alice” age = 25 formatted_string = f”Name: {name:>10} | Age: {age:03}”
print(formatted_string)
Output:
Name: Alice | Age: 025
In this example, the format specification >10 ensures that the value of name is right-
aligned within a field of width 10, padded with spaces if necessary. The format
specification 03 ensures that the value of age is zero-padded to a width of 3.
Specifying Floating-Point Precision:
For floating-point values, you can specify the precision (number of decimal places) using
the format specification .n. For example:
pi = 3.14159 formatted_number = f”Value of pi: {pi:.2f}” print(formatted_number)
Output:
Value of pi: 3.14
In this example, the format specification :.2f ensures that the value of pi is formatted as a
float with two decimal places.
Formatting Numeric Representations:
You can format numeric values using additional format specifications. For example:
number = 42 formatted_number = f”Number: {number:b} {number:x}”
print(formatted_number)
Output:
Number: 101010 2a

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In this example, the format specifications :b and format the value of number as binary and
hexadecimal representations, respectively.
Python f-String
In Python, f-strings (formatted string literals) provide a concise and expressive way to
create formatted strings. F-strings allow you to embed expressions and variables directly
within curly braces {} inside a string, making it easy to combine values and formatting in a
readable manner.
Here’s the basic syntax of an f-string:
variable = value formatted_string = f”Some text {variable} more text”
In this syntax, the expression {variable} is evaluated and replaced with the value of the
variable within the resulting formatted string.
Here are some examples to illustrate the usage of f-strings:
name = “Alice” age = 25 formatted_string = f”My name is {name} and I am {age} years
old.” print(formatted_string)
Output:
My name is Alice and I am 25 years old.
In this example, the values of name and age are directly embedded within the string using
f-string syntax.
You can also include expressions and perform operations within the curly braces:
a = 5 b = 3 formatted_string = f”The sum of {a} and {b} is {a + b}.” print(formatted_string)
Output:
The sum of 5 and 3 is 8.
In this example, the expression {a + b} is evaluated and the result is inserted into the
formatted string.
F-strings also support various formatting options, such as specifying width, alignment,
and precision for numeric values. You can apply these formatting options by adding a
colon : followed by a format specifier inside the curly braces.
pi = 3.14159 formatted_number = f”The value of pi is approximately {pi:.2f}”
print(formatted_number)
Output:
The value of pi is approximately 3.14

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In this example, the format specifier :.2f formats the value of pi as a float with two decimal
places.
F-strings offer a powerful and intuitive way to create formatted strings in Python, allowing
you to combine values, expressions, and formatting options in a clear and concise
manner.
Python Format
In Python, the format() method is a built-in method that allows you to format strings by
replacing placeholders with specified values. It provides a flexible and powerful way to
format strings using various formatting options.
The basic syntax of the format() method is as follows:
formatted_string = “Some text {} more text”.format(value1, value2, …)
In this syntax, curly braces {} are used as placeholders within the string, and the format()
method is called on the string object. The values you want to insert into the placeholders
are passed as arguments to the format() method.
Here are some examples to illustrate the usage of the format() method:
name = “Alice” age = 25 formatted_string = “My name is {} and I am {} years
old.”.format(name, age) print(formatted_string)
Output:
My name is Alice and I am 25 years old.
In this example, the placeholders {} are replaced with the values of name and age passed
to the format() method.
You can also specify the position of the arguments to control their placement within the
formatted string:
name = “Alice” age = 25 formatted_string = “My name is {0} and I am {1} years
old.”.format(name, age) print(formatted_string)
Output:
My name is Alice and I am 25 years old.
In this example, {0} and {1} indicate the positions of the arguments name and age,
respectively.
The format() method also supports various formatting options using format specifiers. For
example, you can specify the width, alignment, precision, and data type of the formatted
values. Here’s an example:

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pi = 3.14159 formatted_number = “The value of pi is approximately {:.2f}”.format(pi)
print(formatted_number)
Output:
The value of pi is approximately 3.14
In this example, the format specifier :.2f is used to format the value of pi as a float with
two decimal places.
The format() method provides extensive formatting capabilities.
Note that in recent versions of Python (3.6 and above), f-strings (formatted string literals)
offer a more concise and readable alternative for string formatting. You might consider
using f-strings instead of the format() method for new code.
Python Print Format
In Python, the print() function is used to display output on the console. By default, it prints
the specified arguments to the console as separate values, with a space character
between them. However, you can also apply formatting to the values passed to print()
using various techniques.
String Concatenation:
You can concatenate strings using the + operator to format the output:
name = “Alice” age = 25 print(“My name is “ + name + ” and I am “ + str(age) + ” years
old.”)
Output:
My name is Alice and I am 25 years old.
In this example, the strings and variables are concatenated using the + operator, and the
str() function is used to convert the age variable to a string.
Comma Separation:
When multiple values are passed as arguments to print(), they are printed with a space
character between them by default. You can change this behavior by specifying the sep
parameter to define the separator:
name = “Alice” age = 25 print(“My name is”, name, “and I am”, age, “years old.”, sep=“|”)
Output:
My name is|Alice|and I am|25|years old.

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In this example, the sep parameter is set to “|” to separate the values with a pipe
character instead of a space.
f-strings (formatted string literals):
Starting from Python 3.6, you can use f-strings to easily format the output within the
print() function:
name = “Alice” age = 25 print(f”My name is {name} and I am {age} years old.”)
Output:
My name is Alice and I am 25 years old.
In this example, the values are directly embedded within the string using f-string syntax.
These are a few examples of formatting output with the print() function in Python.
Depending on your specific requirements, you can choose the method that best suits your
needs.
Python String Formatting Cheat Sheet
Certainly! Here’s a cheat sheet for string formatting in Python:
String Interpolation with % Operator (old-style formatting):
name = “Alice” age = 25 print(“My name is %s and I am %d years old.” % (name, age))
Using .format() method (new-style formatting):
name = “Alice” age = 25 print(“My name is {} and I am {} years old.”.format(name, age))
f-strings (formatted string literals):
name = “Alice” age = 25 print(f”My name is {name} and I am {age} years old.”)
Formatting Floating-Point Numbers:
pi = 3.14159 print(“Value of pi: {:.2f}”.format(pi))
Specifying Width and Alignment:
name = “Alice” print(“Name: {:>10}”.format(name)) # Right-aligned, width of 10
Zero Padding for Integers:
number = 42 print(“Number: {:03}”.format(number)) # Zero-padded, width of 3
Formatting Binary and Hexadecimal Numbers:

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number = 42 print(“Binary: {:b}”.format(number)) print(“Hexadecimal:
{:x}”.format(number))
Using Named Arguments:
name = “Alice” age = 25 print(“My name is {name} and I am {age} years
old.”.format(name=name, age=age))
These are just a few examples of string formatting techniques in Python. There are
additional formatting options and techniques available.
Python Format Number
In Python, you can format numbers using the format() method, f-strings (formatted string
literals), or the % operator. Here are some examples of formatting numbers in Python:
Using the format() method:
number = 123456.789 formatted_number = format(number, “,.2f”)
print(formatted_number)
Output:
123,456.79
In this example, the format() method is used to format the number with a comma as a
thousands separator and a precision of 2 decimal places.
Using f-strings:
number = 123456.789 formatted_number = f”{number:,.2f}” print(formatted_number)
Output:
123,456.79
In this example, the f-string syntax is used with a format specifier :,.2f to achieve the
same formatting result.
Using the % operator (old-style formatting):
number = 123456.789 formatted_number = “%0.2f” % number print(formatted_number)
Output:
123456.79
In this example, the % operator is used with the format specifier %0.2f to format the
number with 2 decimal places.

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These are just a few examples of how you can format numbers in Python. You can
customize the format specifiers to suit your specific requirements when it comes to
Python strings format.
Python Strings Format Syntax
string.format(value1, value2…)
Parameter Values
Parameter Overview
value1,
value2…
In Python strings format it is essential that the values can be either a list
of values separated by commas, a list of keys and values, or a
combination of both. The values can be of any data type.
A formatted string is returned by the format() method.
Execute
Example
1
2
3
mrx = 128
txt = "This is Elon Must and I'll live till " + mrx
print(txt)
Python strings format allows us to combine strings and numbers with format() method.
The Placeholders
Using format(), the passed arguments are formatted and placed in the string where the
placeholders {} are:
Numbers can be inserted into strings using the format() method:
Example

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1
2
3
mrx = 128
txt = "This is Elon MusK and I'll live till {}"
print(txt.format(mrx))
In addition to named indices [price], numbered indices [0], and even empty placeholders
[] can be used to identify placeholders.
Placing placeholders differently:
Example
1
2
3
4
5
6
vartxt1 = "This is {fname}, and I'm {age}".format(fname = "Elon Reeve Musk", age = 51)
vartxt2 = "This is {0}, and I'm {1}".format("Elon Reeve Musk",51)
vartxt3 = "This is {}, and I'm {}".format("Elon Reeve Musk",51)
print(vartxt1)
print(vartxt2)
print(vartxt3)
Put a fixed point, two-decimal price inside the placeholder:
Example
1
2
3
vartxt = "Only {price:.2f} dollars!"
print(vartxt.format(price = 99))
When we talk about Python strings format then, using the format() method in Python,
we can input any number of arguments in the following placeholders:
Execute

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Example
1
2
3
4
5
quantity = 8
productno = 786
price = 99.99
myorder = "Give me {} Numbers of item {} for {} US Dollars."
print(myorder.format(quantity,productno, price))
Place the arguments in the correct placeholders by using index numbers [0]:
Execute
Example
1
2
3
4
5
quantity = 8
productno = 786
price = 99.99
myorder = "I'll Pay for {2} dollars for {0} pieces of item {1}."
print(myorder.format(quantity,productno, price))
Formatting Types
Placeholders can be formatted using the following formatting types in Python strings
format:
:< Execute In the available space, align the results to the left
:> Execute The result is aligned to the right

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:^ Execute The result is aligned to the center
:= Execute Position the sign to the left
:+ Execute Positive or negative results are indicated by a plus sign
:- Execute For negative values, use a minus sign
: Execute Add a space before positive numbers (and a minus sign before negative
numbers).
:, Execute Comma as a thousand (1000) separator
:_ Execute Separate thousand with an underscore
:b Execute Binary format
:c Unicode character conversion
:d Execute Decimal format
:e Execute Lowercase m, scientific format
:E Execute Uppercase M for scientific format
:f Execute Point number fix
:F Execute Numbers should be in uppercase (INF, NAN).
:g General format
:G The general format (using upper case E for scientific notations)
:o Execute Formatted in octal
:x Execute Lowercase hex format
:X Execute Formatted in hexadecimal, upper case
:n Format for numbers

20. 20/20
:% Execute Format for percentages
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