Python multi-line bash command

Question

I am trying to run this:

python -c "for i in range(10):\n print i" 

but I get an error:

 File "<string>", line 1 for i in range(10):\n print i ^ SyntaxError: unexpected character after line continuation character 

According to this , I assume that bash should have handled (namely, a newline) command line arguments, but the error returned shows the opposite. Where am I mistaken and why is this happening?

PS Python-2.7

EDIT

Let me explain my motivation a bit. This sample code is definitely pretty dumb. Since the document says that " command can be one or more statements, separated by newlines, with significant leading spaces, as in normal modular code," I was interested in how to properly bring those mentioned newlines to command . Suggested solutions here:

• Use ; to distinguish several commands within a loop. Yes, it works, but it is still single-line, I cannot use it. If I want to run some commands after a loop. ; not a newline replacement.

• Enter ^M where a new line is required. This more closely matches the goal, but, unfortunately, from my point of view, it basically destroys the whole idea of ​​running python code from the command line, because it requires interactive mode. As I understand it, this is the same as entering the ant command by pressing Enter . Therefore, there is no difference in python input and work in its shell. However, I cannot write this in a bash script. Or can I?

Probably the question really should have been divided into two:

• Bash shielding:

  Double-quoted closing characters ('") keep the literal value of all characters in quotation marks, except for' $, ' ', '\', and, when history expansion is enabled, '!'. The characters '$' and ' retain their the special meaning in double quotes (see the "Shell Extensions" section). its special meaning, followed by only one of the following characters: '$,' `, '', '\ or newline.

How does this fit the case described? How does bash handle newlines? I found that entering the command in unary quotation marks does not make any changes.

2. How to pass a new line in python in a non-interactive way. (You can say - why don't you write a regular python file with all the new lines you want - you're right, but I'm interested in what exactly is meant in the documentation, as it quotes a new line).

Answer 1

You really need to convert the \n part to the actual newline. This can be done using the $'' syntax:

 python -c $'for i in range(10):\n print i' 0 1 2 3 4 5 6 7 8 9 

You can also achieve this result with echo -e or printf

 $ python -c "$(echo -e "for i in range(10):\n print i")" 

You can also use the following line:

 $ python <<< $(echo -e "for i in range(10):\n print i") 

See section 3.1.2.4 Quote ANSI-C Bash Manpage for more information.

Answer 2

Remove \n

 python -c "for i in range(10): print i" 

Or

You can use ; to use multiple lines in a loop

 python -c "for i in range(10): print '1st newline';print '2nd newline';print i" 

Answer 3

You can run the multi-line python -c statement by adding CR characters to your line:

 python -c "for i in range(10):^M print (i)^M print ('Hello:' + str(i*i))" 

where ^ M doesn't really follow ^, followed by M, it's actually the character you get when you enter [CTRL-v] [CTRL-m]. Note the space after this character, which means that there are two print statements in the for loop, and it should print:

 0 Hello:0 1 Hello:1 .... 9 Hello:81 

You can do this in a bash script too:

 #!/bin/bash A="python -c \"for i in range(10):^M print (i)^M print ('Hello:' + str(i*i))\"" eval $A