CODEWITHSUNDEEP
pythonstring
reox
reox

Reputation: 5237

Conditional formatting using pyformat

Given some variable

flag = True
x = "hello"
y = "world"

I would like to print the following string:

"hello world" if flag is True or "hello 'world'" if flag is False. This could be done using the following statement:

print("{} {}".format(x, y if flag else "'{}'".format(y)))

The question is, can such a conditional format be specified directly using pyformat? I.e. is it possible to specify different format strings depending on some variable?

One solution might be to do two formats:

'{{}} {}'.format("{}" if flag else "'{}'").format(x, y)

But this makes it very hard to read as you have to escape the not replaced formats in the first string.

Upvotes: 2

Views: 294

Answers (4)

Artog
Artog

Reputation: 1142

Although I like @schwobaseggl's solution alot, I feel that you're better of just doing a proper if:

if flag:
    print(f"{x} {y}")
else:
    print(f"{x} '{y}')

This will make your code much more readable and maintainable. Otherwise it feel's like you're just trying to hide away the if and making spaghetti.

Upvotes: 1

shaik moeed
shaik moeed

Reputation: 5795

Try this,

>>> print("{x} {flag}{y}{flag}".format(x=x,y=y, flag= "" if flag else "'"))
hello world
>>> flag = False
>>> print("{x} {flag}{y}{flag}".format(x=x,y=y, flag= "" if flag else "'"))
hello 'world'

Upvotes: 0

user2390182
user2390182

Reputation: 73498

I do not think it is possible to select different format strings like that. In your concrete case, you could be more concise with some trickery:

("{} '{}'", "{} {}")[flag].format(x, y)
# 'hello world'
flag = False
("{} '{}'", "{} {}")[flag].format(x, y)
# "hello 'world'"

In general, a dict mapping of possible values of the controlling variable to their corresponding format strings would be simple enough.

Upvotes: 0

dejanualex
dejanualex

Reputation: 4358

If you have python 3.6 or greater, you can use f'strings: print(f"{x} {y}" if flag else f"{x} '{y}'"). More info: https://www.python.org/dev/peps/pep-0498/

Upvotes: 0

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