Flip exec and shell chars (#7)

Makefile

@@ -1,6 +1,6 @@
 check: lint test
 
-SOURCE_FILES=pybash test_pybash.py run.py
+SOURCE_FILES=pybash test_pybash.py
 
 install:
 	pip install -e .

README.md

@@ -5,9 +5,9 @@
 ![PyPI](https://img.shields.io/pypi/v/pybash)
 ![GitHub](https://img.shields.io/github/license/jaykv/pybash)
 
-Streamline bash-command execution from python with a new syntax. It combines the simplicity of writing bash scripts with the flexibility of python. Under the hood, any line or variable assignment starting with `>` or surrounded by parentheses is transformed to python `subprocess` calls and then injected into `sys.meta_path` as an import hook. All possible thanks to the wonderful [ideas](https://github.com/aroberge/ideas) project!
+Streamline bash-command execution from python with a new syntax. It combines the simplicity of writing bash scripts with the flexibility of python. Under the hood, any line or variable assignment starting with `$` or surrounded by parentheses is transformed to python `subprocess` calls and then injected into `sys.meta_path` as an import hook. All possible thanks to the wonderful [ideas](https://github.com/aroberge/ideas) project!
 
-For security and performance reasons, PyBash will NOT execute as shell, unless explicitly specified with a `$` instead of a single `>` before the command. While running commands as shell can be convenient, it can also spawn security risks if you're not too careful. If you're curious about the transformations, look at the [unit tests](test_pybash.py) for some quick examples.
+For security and performance reasons, PyBash will NOT execute as shell, unless explicitly specified with a `>` instead of a single `$` before the command. While running commands as shell can be convenient, it can also spawn security risks if you're not too careful. If you're curious about the transformations, look at the [unit tests](test_pybash.py) for some quick examples.
 
 Note: this is a mainly experimental library.
 
@@ -20,7 +20,7 @@ Note: this is a mainly experimental library.
 ```python
 from pybash.transformer import transform
 
-transform(">echo hello world") # returns the python code for the bash command as string
+transform("$echo hello world") # returns the python code for the bash command as string
 ```
 
 ## As script runner
@@ -31,20 +31,20 @@ transform(">echo hello world") # returns the python code for the bash command as
 ```py
 #
 text = "HELLO WORLD"
->echo f{text}
+$echo f{text}
 ```
 
 ### Run script:
 ```bash
-$ python -m pybash hello.py
+python -m pybash hello.py
 ```
 
 # Supported transforms
 
 ### 1. Simple execution with output
 ```python
->python --version
->echo \\nthis is an echo
+$python --version
+$echo \\nthis is an echo
 ```
 outputs:
 ```
@@ -55,7 +55,7 @@ this is an echo
 
 ### 2. Set output to variable and parse
 ```python
-out = >cat test.txt
+out = $cat test.txt
 test_data = out.decode('utf-8').strip()
 print(test_data.replace("HELLO", "HOWDY"))
 ```
@@ -66,7 +66,7 @@ HOWDY WORLD
 
 ### 3. Wrapped, in-line execution and parsing
 ```python
-print((>cat test.txt).decode('utf-8').strip())
+print(($cat test.txt).decode('utf-8').strip())
 ```
 outputs:
 ```
@@ -75,12 +75,12 @@ HELLO WORLD
 
 ### 4. Redirection
 ```python
->echo "hello" >> test4.txt
+$echo "hello" >> test4.txt
 ```
 
 ### 5. Pipe chaining
 ```python
->cat test.txt | sed 's/HELLO/HOWDY/g' | sed 's/HOW/WHY/g' | sed 's/WHY/WHEN/g'
+$cat test.txt | sed 's/HELLO/HOWDY/g' | sed 's/HOW/WHY/g' | sed 's/WHY/WHEN/g'
 ```
 outputs:
 ```
@@ -89,25 +89,25 @@ WHENDY WORLD
 
 ### 6. Redirection chaining
 ```python
->cat test.txt | sed 's/HELLO/HOWDY\\n/g' > test1.txt >> test2.txt > test3.txt
+$cat test.txt | sed 's/HELLO/HOWDY\\n/g' > test1.txt >> test2.txt > test3.txt
 ```
 
 ### 7. Chaining pipes and redirection- works in tandem!
 ```python
->cat test.txt | sed 's/HELLO/HOWDY\\n/g' > test5.txt
+$cat test.txt | sed 's/HELLO/HOWDY\\n/g' > test5.txt
 ```
 
 ### 8. Input redirection
 ```python
->sort < test.txt >> sorted_test.txt
+$sort < test.txt >> sorted_test.txt
 ```
 
 ```python
->sort < test.txt | sed 's/SORT/TEST\\n/g'
+$sort < test.txt | sed 's/SORT/TEST\\n/g'
 ```
 ### 9. Glob patterns with shell
 ```python
-$ls .github/*
+>ls .github/*
 ```
 
 ### 10. Direct interpolation
@@ -118,21 +118,21 @@ Denoted by {{code here}}. Interpolated as direct code replace. The value/output
 command = "status"
 def get_option(command):
     return "-s" if command == "status" else "-v"
->git {{command}} {{get_option(command)}}
+$git {{command}} {{get_option(command)}}
 
 display_type = "labels"
->kubectl get pods --show-{{display_type}}=true
+$kubectl get pods --show-{{display_type}}=true
 
 ## BAD
 option = "-s -v"
->git status {{option}}
+$git status {{option}}
 
 options = ['-s', '-v']
->git status {{" ".join(options)}}
+$git status {{" ".join(options)}}
 
 # use dynamic interpolation
 options = {'version': '-v'}
->git status {{options['version']}}
+$git status {{options['version']}}
 ```
 
 ### 11. f-string interpolation
@@ -143,22 +143,22 @@ Denoted by f{ any python variable, function call, or expression here }. Interpol
 
 # git -h
 options = {'version': '-v', 'help': '-h'}
->git f{options['h']}
+$git f{options['h']}
 
 # kubectl get pods --show-labels -n coffee
 namespace = "coffee"
->kubectl get pods f{"--" + "-".join(['show', 'labels'])} -n f{namespace}
+$kubectl get pods f{"--" + "-".join(['show', 'labels'])} -n f{namespace}
 
 ## BAD
 option = "-s -v"
->git status f{option}
+$git status f{option}
 ```
 
 #### Also works inside methods!
 ```python
 # PYBASH DEMO #
 def cp_test():
-    >cp test.txt test_copy.txt
+    $cp test.txt test_copy.txt
 
 cp_test()
 ```

examples/demo.py

@@ -1,59 +1,60 @@
 # PYBASH DEMO #
+# run with either: python run.py or python -m pybash demo.py
 
 # dynamic interpolation
 options = {'version': '-v', 'help': '-h'}
->git f{options['help']}
+$git f{options['help']}
 
 namespace = "coffee"
->kubectl get pods f{"--" + "-".join(['show', 'labels'])} --namespace f{namespace}
+$kubectl get pods f{"--" + "-".join(['show', 'labels'])} --namespace f{namespace}
 
 # static interpolation
 git_command = "status"
 option = "-v"
 
->git {{git_command}} {{option}}
+$git {{git_command}} {{option}}
 
 #TODO:
-#a = >echo "hello" >> test.txt
-#a = >sort < test.txt | grep "HELLO"
+#a = $echo "hello" >> test.txt
+#a = $sort < test.txt | grep "HELLO"
 #print(f"test: {a}")
 
 # 1. use inside methods
->echo "SORT TEST\nHELLO WORLD" > test.txt
+$echo "SORT TEST\nHELLO WORLD" > test.txt
 def cp_test():
     print("1. >cp test.txt test_copy.txt")
-    >cp test.txt test_copy.txt
+    $cp test.txt test_copy.txt
 
 cp_test()
 
 # 2. simple bash command execution with output
 print("2. >python --version\n   >echo \\nthis is an echo")
->python --version
->echo \\nthis is an echo
+$python --version
+$echo \\nthis is an echo
 
 # 3. set output to python variable directly
-out = >cat test.txt
+out = $cat test.txt
 test_data = out.decode('utf-8').strip()
 print(test_data.replace("HELLO", "HOWDY"))
 
 # 4. wrapped, in-line execution
-print((>cat test.txt).decode('utf-8').strip())
+print(($cat test.txt).decode('utf-8').strip())
 
 # 5. redirection
->echo "hello" >> test4.txt
+$echo "hello" >> test4.txt
 
 # 6. pipe chaining
->cat test.txt | sed 's/HELLO/HOWDY/g' | sed 's/HOW/WHY/g' | sed 's/WHY/WHEN/g'
+$cat test.txt | sed 's/HELLO/HOWDY/g' | sed 's/HOW/WHY/g' | sed 's/WHY/WHEN/g'
 
 # 7. chaining pipes and redirection- works with all!
->cat test.txt | sed 's/HELLO/HOWDY\\n/g' > test5.txt
+$cat test.txt | sed 's/HELLO/HOWDY\\n/g' > test5.txt
 
 # 8. chained redirection
->cat test.txt | sed 's/HELLO/HOWDY\\n/g' > test1.txt >> test2.txt > test3.txt
+$cat test.txt | sed 's/HELLO/HOWDY\\n/g' > test1.txt >> test2.txt > test3.txt
 
 # 9. input redirection
->sort < test.txt >> sorted_test.txt
->sort < test.txt | sed 's/SORT/TEST\\n/g'
+$sort < test.txt >> sorted_test.txt
+$sort < test.txt | sed 's/SORT/TEST\\n/g'
 
 # 10. Glob patterns
-$ls .github/*
+>ls ./*

examples/hello.py

@@ -1,3 +1,3 @@
 
 text = "HELLO WORLD"
->echo f{text}
+$ echo f{text}

run.py → examples/run.py

@@ -9,4 +9,4 @@
 if __name__ == "__main__":
     import demo
 
-    print(f"running {demo}")
+    print(f"~ completed running {demo}")

pybash/transformer.py

@@ -10,7 +10,7 @@ class InvalidInterpolation(Exception):
 
 
 class Processor:
-    command_char = ">"
+    command_char = "$"
 
     def __init__(self, token: token_utils.Token) -> None:
         self.token = token
@@ -78,7 +78,7 @@ def direct_interpolate(string: str) -> str:
 
 class Shelled(Processor):
     # $ls .github/*
-    command_char = "$"
+    command_char = ">"
 
     def transform(self) -> token_utils.Token:
         command_str = " ".join(self.command)
@@ -107,12 +107,13 @@ def parse(self) -> None:
 
     def transform(self) -> None:
         pipeline_command = Pipeline(self.command).parse_command(variablized=True)
+
         if pipeline_command != self.command:
             self.token.string = pipeline_command
             self.token.string += ';' if pipeline_command[-1] != ';' else ''
             self.token.string += ' '.join(self.parsed_line[: self.start_index]) + ' cmd1\n'
         else:
-            self.token.string = ' '.join(self.parsed_line[: self.start_index])
+            self.token.string = ' '.join(self.parsed_line[: self.start_index]) + ' '
             self.token.string += Commander.build_subprocess_list_cmd("check_output", self.command) + '\n'
 
 
@@ -128,7 +129,7 @@ def transform(self) -> token_utils.Token:
         # shlex strips out single quotes and double quotes-- use raw_line for the code around the wrapped command
         self.token.string = (
             ' '.join(self.raw_line[: self.start_index])
-            + self.raw_line[self.start_index][: self.raw_line[self.start_index].index('>')]
+            + self.raw_line[self.start_index][: self.raw_line[self.start_index].index('$')]
         )
         self.token.string += (
             Commander.build_subprocess_list_cmd("check_output", self.command)
@@ -329,7 +330,7 @@ def get_start_index(parsed_line: list) -> int:
             int: starting index
         """
         for i, val in enumerate(parsed_line):
-            if '>' in val:
+            if '$' in val:
                 return i
 
         return 0
@@ -339,7 +340,7 @@ def get_bash_command(
         parsed_line: list,
         start_index: Union[int, None] = None,
         wrapped: Union[bool, None] = None,
-        command_char: str = ">",
+        command_char: str = "$",
     ) -> list:
         """Parses line to bash command
 
@@ -361,6 +362,8 @@ def get_bash_command(
         # > may be at the beginning or somewhere in the middle of this arg
         # examples: >ls, print(>cat => strip up to and including >
         command[0] = command[0][command[0].index(command_char) + 1 :].strip()
+        if command[0] == '':
+            del command[0]
 
         # remove everything after and including first )- not part of the command
         if wrapped:
@@ -412,8 +415,8 @@ def build_subprocess_list_cmd(method: str, args: list, **kwargs) -> str:
         return command
 
 
-TOKENIZERS = {"$": Shelled, ">": Execed}
-GREEDY_TOKENIZERS = {"= >": Variablized, "(>": Wrapped}
+TOKENIZERS = {">": Shelled, "$": Execed}
+GREEDY_TOKENIZERS = {"= $": Variablized, "($": Wrapped}
 
 
 def transform(source, **_kwargs):
@@ -443,3 +446,8 @@ def transform(source, **_kwargs):
         new_tokens.extend(line)
 
     return token_utils.untokenize(new_tokens)
+
+
+if __name__ == "__main__":
+    pyscript = transform("test = $ echo hi")
+    print(pyscript)

pyproject.toml

@@ -1,6 +1,6 @@
 [tool.poetry]
 name = "PyBash"
-version = "0.3.1"
+version = "0.3.2"
 description = ">execute bash commands from python easily"
 authors = ["Jay <jay.github0@gmail.com>"]
 readme = "README.md"