The problem has nothing to do with the command line, it's caused by
trying to use a keyword 'while' somewhere other than the beginning of
the statement.

I'll ask you the same question I had:  why do you bother?  What's wrong
with making a separate file for the source code?

But as for solutions, first question is what OS you're running on.  If
not Windows, you can probably use \n at appropriate points.

If that's not good enough, what about simply running the script instead
of a batch file?

If that's not good enough, how about merging the two languages, with a
trick like starting the python code with rem = """  followed by the
shell script?

There are many others, but we cannot choose without knowing your other
constraints.

--

[steve@ando ~]$ python -c "pass; pass"
[steve@ando ~]$ python -c "pass; if True:        pass"
  File "<string>", line 1
    pass; if True:       pass
           ^
SyntaxError: invalid syntax

Solution: don't use semi-colons, use newlines.

In this example, I use `Ctrl-Q ENTER` to insert a literal newline in the
string, which shows as ^M. Note that you *cannot* just type ^ M (caret
M), that won't work, it must be an actual control character.

[steve@ando ~]$ python -c 'import time^Mwhile True:^M    print("hello"); time.sleep(2)'
hello
hello
hello
Traceback (most recent call last):
  File "<string>", line 3, in <module>
KeyboardInterrupt

In this example I just hit the Enter key to insert a newline, and let the
shell deal with it. The ">" marks are part of the shell's prompt.

[steve@ando ~]$ python -c "import time

python - <<EOF
import os
while True:
    print('hello')
EOF

The "-" tells the Python interpreter to read from stdin.  The shell
supplies the lines between the <<EOF and the matching EOF as stdin.

http://en.wikipedia.org/wiki/Here_document

http://docs.python.org/reference/simple_stmts.html

“Several simple statements may occur on a single line separated by
semicolons.”

Anyways, this does not explicitly say “You shall not put a compound
statement after a simple statement separated by a semicolon.”, right?

In my opinion, this is a major wart in Python syntax. You can argue
all you like about how it reduces code clarity to put these sorts of
things together, but that's a job for a style guide, NOT a language
requirement. Most code won't put an assignment followed by an
if/while/for, but when I'm working interactively, I often want to
recall an entire statement to edit and reuse, complete with its
initialization - something like (contrived example):

To force that sort of thing to be a single recallable statement, I can
do stupid tricks like:

but that only works in IDLE, not in command-line interactive Python.

Note, by the way, that it's fine to put the statement _inside_ the for
on the same line. It's even legal to have multiple such statements:

If there's any ambiguity, it would surely be that, and not the simple
statement being first.

Okay, rant over. I'll go back to being nice now. :)

Here's a side challenge. In any shell you like, start with this
failing statement, and then fix it without retyping anything:

sikorsky@sikorsky:~$ python -c "a=1; if a: print(a)"
  File "<string>", line 1
    a=1; if a: print(a)
          ^
SyntaxError: invalid syntax

In bash, I was unable to insert a newline into the quoted string. My
only option was to backspace everything after the point where I wanted
the newline, then hit enter, then retype the if. I'm curious to know
if that's simply because I didn't think of (some bash feature), or
alternatively, if there's another shell that would have made this
easy.

Back to the main point. In C-like languages, the newline is nothing
special. (ECMAScript allows the omission of semicolons at end of line
in many cases, but many style guides recommend using them anyway.) You
can, if you so desire, put all your code into a single line. It's then
up to the project's style guide to decide how things should be laid
out. For instance, this is multiple statements in PHP, but I see it as
one logical action:

$bar=array(); for ($foo as $k=>$v) $bar[$k]="<p>".$v."</p>";

It's one statement in Python:

bar = ["<p>"+x+"</p>" for x in foo]

It's one statement in Pike:

array bar = map(foo,lambda(string x) {return "<p>"+x+"</p>";});

So it should be allowed to be put on one line. And in languages whose
syntax derives from C, you almost certainly can. (I can't think of any
counter-examples, though that certainly doesn't prove they don't
exist.) But the same thing is forced onto two lines in Python, and not
for syntactic reasons - at least, not that I can see. Perhaps someone
can enlighten me.

Is there any fundamental reason that the syntax couldn't be expanded
to permit "statement; statement" for any two given statements?

*stashes that away in the "handy commands" index in his brain*

The semicolon separates statements, but doesn't change nesting levels.
The if statement increases the nesting level, which demands a
corresponding indentation increase if you go onto a new line; the
statement you describe is illegal because the 'if' isn't allowed to
not be at the beginning of the line, but it's unambiguous.

Of course, since Python lacks a non-whitespace way of indicating the
end of an if block, there's no way to put your "if A" and "if B" onto
the same line as peers. But that's a consequence of a design decision,
and one that can't easily be changed. Every language has warts like
that; eschewing variable declarations prevents infinite nesting of
scopes, but demanding variable declarations makes interactive work
harder. To paraphrase the Pirate King: Always follow the dictates of
your conscience, and accept the consequences.