When space matters and when not?

Question

In "print( "Hi" )" space don't matters, but in ">>> print("hi)" that space after ">>>" makes an error in the code.

Answer 1

In Python, space matters at the beginning of each line, because Python uses indentation for controlling the program flow.

If a line of code is not in a block, it needs to be right at the left side, with no space.

If it's in a block, it HAS TO be indented, but exactly like the other lines in the block.

if 1>0:
print(1)
print(2)
print(3)

The last line is a mistake:

It is in the block, but not in alignment with the other lines.