use warnings;
use strict;
use autodie; # this is the "magic to handle failure" of open

... {
    open my $fh, '<', 'welcome.txt';
    ...
} # auto closes file handle when $fh goes out of context
...
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The major difference here is that, where Python uses explicit magic, Perl uses garbage collection. Perl's reference counting garbage collector is extremely efficient, even though it leaks memory with reference cycles. As a result, not only is open my $fh, ... more efficient, with no extra runtime magic to support a filehandle upon entering the block, it is also possible to pass $fh as a return value or store it in some structure such that it will outlast the scope in which it was opened. Garbage collection means that lexical and dynamic scopes are independent.

The with open(...) as fh: construct in Python is shorthand for a try/finally block that ensures fh is closed when execution leaves the block. Perl is far more flexible here: files are closed explicitly with close or implicitly when their handles are garbage-collected. (This is why bareword filehandles must be explicitly closed: package variables remain in-scope until the interpreter exits.)

Again, in Perl filehandles remain open (unless explicitly closed) as long as references to them exist, while the Python with open(...) as fh: construct limits both the lexical and dynamic extent of the filehandle.

Python:

with open("welcome.txt") as file: 
    ... # do stuff
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Perl:

{ # can be any block; sub, named or just empty

    open my $fh, 'welcome.txt' or die "couldn't open file!: $!";
    ... # do stuff
}

# file is auto-closed here
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"There is a context manager magic to handle failure in python."

Python isn't as 'scope context sensitive' as Perl is in some regards. In Python, the "with" context is no more than a block encapsulated within braces in Perl. Essentially, in Python, the "with" signifies what is called a 'block' or 'scope' in Perl. It simply means everything indented underneath of this "with" will be automatically garbage collected/files closed when the block (ie. context) exits (in basic usage).

open my $fh, '<', 'welcome.txt';
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Adding a die will allow you to invoke exception semantics. This can often be used as a way to avoid having to do a if file exists check with -e before attempting to open an existing file for reading, for example:

open my $fh, '<', 'welcome.txt' or die "couldn't open file for reading
+!: $!";
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* Scoping in Perl is generally easy to explain, but there's a lot to it. See documention on my, our, and perlsub as a good start.