My friend gave my this code in Python:
a ,= 1------1,
print(a)
The output is 2. But why? Can somebody explain how it works?
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1`1 - (-1)` is 2. Same but with more minus signs. – khelwood Jun 12 '21 at 21:03
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But how about this commas before `=` and on the very end of the line? – dan Jun 12 '21 at 21:06
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Teaching you basic language syntax is off-topic for Stack Overflow. Look up unary minus and subtraction. – Prune Jun 12 '21 at 21:06
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1You're setting a tuple containing `a` to a tuple containing 2. That has the same effect as setting `a` to 2. – khelwood Jun 12 '21 at 21:07
1 Answers
2
a, = 1------1,
is the same as:
a = 1------1
1-(-(-(-(-(-1)))))
|+| |+| |+|
=> 1 + 1 = 1
You can think of this comma like this:
a = 1 # a is 1
a, = [1] # a is 1
a = [1] # a is [1]
Daniel
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