Python Code Reviewer

Question

Task

Your mission is to create a program that reviews Python code. The solution can be written in any language!

It must take input that contains python code. The program must add # This is not pythonic! before each block of non-whitespace lines.

Input

• The data can be entered via stdin.
• The data will contain at least 3 lines with one blank one in between them.

Minimum input example.

print "Hello World!"

Print "Bye World!"

Sample Input

from os.path import abspath

lines = []
with open(__file__, 'r') as f:
    for line in f:
        lines.append(line)

if lines is not None:

    newLines = []
    hasReviewedBlock = False

    for line in lines:
        if len(line) > 1: # \n
            if hasReviewedBlock == False:
                newLines.append("# This is not pythonic!\n")
                hasReviewedBlock = True
        else:
            hasReviewedBlock = False

        newLines.append(line)
    with open("d:/test.py", 'w') as f:
        for line in newLines:
            f.write(line);

Output

Output has to be written to STDOUT or closest alternative.

Sample Output

# This is not pythonic!
from os.path import abspath

# This is not pythonic!
lines = []
with open(__file__, 'r') as f:
    for line in f:
        lines.append(line)

# This is not pythonic!
if lines is not None:

# This is not pythonic!
    newLines = []
    hasReviewedBlock = False

# This is not pythonic!
    for line in lines:
        if len(line) > 1: # \n
            if hasReviewedBlock == False:
                newLines.append("# This is not pythonic!\n")
                hasReviewedBlock = True
        else:
            hasReviewedBlock = False

# This is not pythonic!
        newLines.append(line)
    with open("d:/test.py", 'w') as f:
        for line in newLines:
            f.write(line);

Scoring:

Lowest number of bytes wins. -5 bytes if your program can be used as valid input.

Answer 1

awk, 64 56 54 bytes

/^$/{i=0}/./{if(!i++)print"# This is not pythonic!"}1

Test:

echo '/^$/{i=0}/./{if(!i++)print"# This is not pythonic!"}1' > solution.awk
awk -f solution.awk < pyth.py
awk -f solution.awk < pyth.py

Explanation:

/^$/ - matches empty line,

/./ - matches non-empty line,

1 - matches each line. No body is equivalent to {print;} - each line of input is printed.

Answer 2

Pyth, 39 38 37 bytes

tjbm|d+b"# This is not pythonic!"+k.z

Live demo.

Explanation

tjbm|d+b"# This is not pythonic!"+k.z
                                 +k.z    Prepend the empty line to the string
   m                                     For each line
    |d                                   If it's non-empty, return the same line
      +b"# This is not pythonic!"        Else, return a line break followed by the required text
 jb                                      Join via line breaks
t                                        Remove the unneeded preceding line break

38-byte version

tjbm?dd+b"# This is not pythonic!"+k.z

39-byte version

jbtsm?dd,d"# This is not pythonic!"+k.z

No doubt there's still golfing left to do.

Answer 3

AutoIt - 139

$1='# This is not pythonic!'
ConsoleWrite($1&@CRLF&StringRegExpReplace(FileRead($CmdLine[1]),'(*BSR_ANYCRLF)(^\R|\R(?=\R))',"\0"&@CRLF&$1))

I'm assuming the first line cannot be empty as by your specification:

The data will contain at least 3 lines with one blank one in between them.

This program is called like this:

compiled.exe pycode.py > output.txt

The RegEx can be optimized for sure. Works for CRLF only.

Answer 4

Wren, 73-5 = 68 bytes

Luckily enough, Wren has an automatic WYSIWYG that gains the bonus.

Fn.new{|i|("

"+i).split("

").join("

# This is not pythonic!
")[2..-1]}

Try it online!

Explanation

Fn.new{|i|    // In this case we define a new
              // anonymous function with the operand i
          ("

"+i)          // We prepend the input with 2 newlines
    .split("

")            // Split the input by newlines,
              // including the preceding newlines
              // that we first prepended
  .join("

# This is not pythonic!
")            // Join the input with 2 newlines
              // , the comment, and another trailing newline
  [2..-1]}    // Slice the input so that the preceding
              // 2 newlines are not present in the final output
```

Answer 5

Perl 6, 40 - 5 = 35 bytes

{S:g/^|"

"<(/# This is not pythonic!
/}

Try it online!

The bonus is rather weird, but it didn't cost me any bytes to add.

Explanation

{S:g/        /   /}  # Substitute all instances of
     ^                 # The start of the string
      |"  "            # or two newlines
           <(          # But don't actually replace, just append
              ...    # With the given string

Answer 6

Python 3, 86 bytes - 5 = 81

import re

print(re.sub(r"(^\n*|\n\n+)",r"\1# This is not pythonic\n",open(0).read()))

Try it online!

---

Python 3, 94 bytes - 5 = 89

p=''

for c in open(0).read().splitlines():print("# This is not pythonic!\n"*(p==''!=c)+c);p=c

Try it online!

Answer 7

CJam, 41 bytes

"# This is not pythonic!":TNqN/{_{T}|}%N*

Try it online

Alternate solution that handles multiple empty lines in succession, as well as empty lines at the start. This is 44 bytes, and will become my solution depending on how the pending clarifications turn out:

qN/{_L!e&{"# This is not pythonic!"\}&:L}%N*

Answer 8

JavaScript (ES6), 70

Test running the snippet below.

f=p=>alert((r='# This is not pythonic!\n')+p.replace(/\n\n+/g,x=>x+r))

//// TEST CASES /////

t1=`print "Hello World!"

Print "Bye World!"`
f(t1)

t2=`from os.path import abspath

lines = []
with open(__file__, 'r') as f:
    for line in f:
        lines.append(line)

if lines is not None:

    newLines = []
    hasReviewedBlock = False

    for line in lines:
        if len(line) > 1: # \n
            if hasReviewedBlock == False:
                newLines.append("# This is not pythonic!\n")
                hasReviewedBlock = True
        else:
            hasReviewedBlock = False

        newLines.append(line)
    with open("d:/test.py", 'w') as f:
        for line in newLines:
            f.write(line);`
f(t2)