"在 Python 中使用字符串格式打印元组"

Question

So, i have this problem. I got tuple (1,2,3) which i should print with string formatting. eg.

tup = (1,2,3)
print "this is a tuple %something" % (tup)

Answer 1

>>> thetuple = (1, 2, 3)
>>> print "this is a tuple: %s" % (thetuple,)
this is a tuple: (1, 2, 3)

Making a singleton tuple with the tuple of interest as the only item, ie the (thetuple,) part, is the key bit here.

Answer 2

Note that the % syntax is obsolete. Use str.format , which is simpler and more readable:

t = 1,2,3
print 'This is a tuple {0}'.format(t)

Answer 3

Many answers given above were correct. The right way to do it is:

>>> thetuple = (1, 2, 3)
>>> print "this is a tuple: %s" % (thetuple,)
this is a tuple: (1, 2, 3)

However, there was a dispute over if the '%' String operator is obsolete. As many have pointed out, it is definitely not obsolete, as the '%' String operator is easier to combine a String statement with a list data.

Example:

>>> tup = (1,2,3)
>>> print "First: %d, Second: %d, Third: %d" % tup
First: 1, Second: 2, Third: 3

However, using the .format() function, you will end up with a verbose statement.

Example:

>>> tup = (1,2,3)
>>> print "First: %d, Second: %d, Third: %d" % tup
>>> print 'First: {}, Second: {}, Third: {}'.format(1,2,3)
>>> print 'First: {0[0]}, Second: {0[1]}, Third: {0[2]}'.format(tup)

First: 1, Second: 2, Third: 3
First: 1, Second: 2, Third: 3
First: 1, Second: 2, Third: 3

Further more, '%' string operator also useful for us to validate the data type such as %s , %d , %i , while .format() only support two conversion flags : '!s' and '!r' .

Answer 4

>>> tup = (1, 2, 3)
>>> print "Here it is: %s" % (tup,)
Here it is: (1, 2, 3)
>>>

Note that (tup,) is a tuple containing a tuple. The outer tuple is the argument to the % operator. The inner tuple is its content, which is actually printed.

(tup) is an expression in brackets, which when evaluated results in tup .

(tup,) with the trailing comma is a tuple, which contains tup as is only member.

Answer 5

This doesn't use string formatting, but you should be able to do:

print 'this is a tuple ', (1, 2, 3)

If you really want to use string formatting:

print 'this is a tuple %s' % str((1, 2, 3))
# or
print 'this is a tuple %s' % ((1, 2, 3),)

Note, this assumes you are using a Python version earlier than 3.0.

Answer 6

Even though this question is quite old and has many different answers, I'd still like to add the imho most "pythonic" and also readable/concise answer.

Since the general tuple printing method is already shown correctly by Antimony, this is an addition for printing each element in a tuple separately, as Fong Kah Chun has shown correctly with the %s syntax.

Interestingly it has been only mentioned in a comment, but using an asterisk operator to unpack the tuple yields full flexibility and readability using the str.format method when printing tuple elements separately .

tup = (1, 2, 3)
print('Element(s) of the tuple: One {0}, two {1}, three {2}'.format(*tup))

This also avoids printing a trailing comma when printing a single-element tuple, as circumvented by Jacob CUI with replace . (Even though imho the trailing comma representation is correct if wanting to preserve the type representation when printing ):

tup = (1, )
print('Element(s) of the tuple: One {0}'.format(*tup))

Answer 7

t = (1, 2, 3)

# the comma (,) concatenates the strings and adds a space
print "this is a tuple", (t)

# format is the most flexible way to do string formatting
print "this is a tuple {0}".format(t)

# classic string formatting
# I use it only when working with older Python versions
print "this is a tuple %s" % repr(t)
print "this is a tuple %s" % str(t)

Answer 8

I think the best way to do this is:

t = (1,2,3)

print "This is a tuple: %s" % str(t)

If you're familiar with printf style formatting, then Python supports its own version. In Python, this is done using the "%" operator applied to strings (an overload of the modulo operator), which takes any string and applies printf-style formatting to it.

In our case, we are telling it to print "This is a tuple: ", and then adding a string "%s", and for the actual string, we're passing in a string representation of the tuple (by calling str(t)).

If you're not familiar with printf style formatting, I highly suggest learning, since it's very standard. Most languages support it in one way or another.

Answer 9

Besides the methods proposed in the other answers, since Python 3.6 you can also use Literal String Interpolation (f-strings):

>>> tup = (1,2,3)
>>> print(f'this is a tuple {tup}')
this is a tuple (1, 2, 3)

Answer 10

Please note a trailing comma will be added if the tuple only has one item. eg:

t = (1,)
print 'this is a tuple {}'.format(t)

and you'll get:

'this is a tuple (1,)'

in some cases eg you want to get a quoted list to be used in mysql query string like

SELECT name FROM students WHERE name IN ('Tom', 'Jerry');

you need to consider to remove the tailing comma use replace(',)', ')') after formatting because it's possible that the tuple has only 1 item like ('Tom',), so the tailing comma needs to be removed:

query_string = 'SELECT name FROM students WHERE name IN {}'.format(t).replace(',)', ')')

Please suggest if you have decent way of removing this comma in the output.

Answer 11

For python 3

tup = (1,2,3)
print("this is a tuple %s" % str(tup))

Answer 12

Try this to get an answer:

>>>d = ('1', '2') 
>>> print("Value: %s" %(d))
Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
TypeError: not all arguments converted during string formatting

If we put only-one tuple inside (), it makes a tuple itself:

>>> (d)
('1', '2')

This means the above print statement will look like: print("Value: %s" %('1', '2')) which is an error!

Hence:

>>> (d,)
(('1', '2'),)
>>> 

Above will be fed correctly to the print's arguments.

Answer 13

You can try this one as well;

tup = (1,2,3)
print("this is a tuple {something}".format(something=tup))

You can't use %something with (tup) just because of packing and unpacking concept with tuple.

Answer 14

Using f-string for a quick print in python3.

tup = (1,2,3)
print(f"this is a tuple {tup}")

Answer 15

how much changed over the years. Now you can do this:

tup = (1,2,3)
print(f'This is a Tuple {tup}.')

Answer 16

Talk is cheap, show you the code:

>>> tup = (10, 20, 30)
>>> i = 50
>>> print '%d      %s'%(i,tup)
50  (10, 20, 30)
>>> print '%s'%(tup,)
(10, 20, 30)
>>>