With, If... statements in python inline code

Question

I want to use python from my bash script, for json parsing and other stuff, having some a syntax error I cannot really understand. So I'd like to deeply understand why this code doesn't work :

>>> import sys, json; if "foo": print("yes")
  File "<stdin>", line 1
    import sys, json; if "foo": print("yes")
                       ^
SyntaxError: invalid syntax

while this one works:

>>> if "foo": print ("yes"); import sys, os
... 
yes

Same as :

>>> import sys, json; with open("foo.json") as fd: print(fd.read())
  File "<stdin>", line 1
    import sys, json; with open("papi.json") as fd: print(fd.read())
                         ^
SyntaxError: invalid syntax

This works :

>>> with open("foo.json") as fd: print(fd.read()); import sys, json
... 
{"repositoryName": "REPOSITORY", "triggers": [{"name": "cc-branches-lifecycle", "destinationArn": "arn:aws:lambda:REGION:ACCOUNT:function:lambda-engineering-codepipeline-cc-lifecycle-RELEASE", "customData": "{\"pipeline_exec_function\": \"arn:aws:lambda:REGION:ACCOUNT:function:lambda-engineering-codepipeline-cc-updates-RELEASE\", \"pipeline_name\": \"PIPELINE\", \"bucket\": \"BUCKET\"}", "branches": [], "events": ["createReference", "deleteReference"]}, {"name": "trigger-DEVBRANCH-updates", "destinationArn": "arn:aws:lambda:REGION:ACCOUNT:function:lambda-engineering-codepipeline-cc-updates-RELEASE", "customData": "{\"pipeline_name\": \"PIPELINE\", \"bucket\": \"BUCKET\"}", "branches": ["DEVBRANCH"], "events": ["updateReference"]}]}

this also works :

   >>> import sys, json; fd = open("foo.json"); print(fd.read())
{"repositoryName": "REPOSITORY", "triggers": [{"name": "cc-branches-lifecycle", "destinationArn": "arn:aws:lambda:REGION:ACCOUNT:function:lambda-engineering-codepipeline-cc-lifecycle-RELEASE", "customData": "{\"pipeline_exec_function\": \"arn:aws:lambda:REGION:ACCOUNT:function:lambda-engineering-codepipeline-cc-updates-RELEASE\", \"pipeline_name\": \"PIPELINE\", \"bucket\": \"BUCKET\"}", "branches": [], "events": ["createReference", "deleteReference"]}, {"name": "trigger-DEVBRANCH-updates", "destinationArn": "arn:aws:lambda:REGION:ACCOUNT:function:lambda-engineering-codepipeline-cc-updates-RELEASE", "customData": "{\"pipeline_name\": \"PIPELINE\", \"bucket\": \"BUCKET\"}", "branches": ["DEVBRANCH"], "events": ["updateReference"]}]}

My origanal comes from the fact I'm trying to update aws codecommit repository triggers from bash. Here is the real command issuing error :

#aws codecommit get-repository-triggers --repository-name $repository | python -c 'import json, sys; triggers = json.load(sys.stdin).get("triggers", []); with open(os.environ["triggersfile"]) as fp: triggers_doc = json.load(fp); triggers_doc["triggers"].extend(triggers); triggers_doc["triggers"] = list({trigger["name"]:trigger for trigger in triggers_doc["triggers"]}.values()); with open(os.environ["triggersfile"], "w") as fd: json.dump(triggers_doc, fd)'

I know I can use open and close statements, but I want to understand why the with statement doent' work.

There is a syntax for `if`: `"something" if condition else "something else"`. Therefore, your `if` gets non-understandable for `python`. I assume that with `with` the same story — Dmytro Chasovskyi, Jan 30 '19 at 16:08
Why are you so curious about writing everything on one line? Multi-line codes add to readability at the cost nothing. — Austin, Jan 30 '19 at 16:10
The code I paste here is to understand why the code embedded in my bash script doesn't work. I know well how the "if" and "with" statement works, read well my question and look at the examples — nixmind, Jan 30 '19 at 16:26
The simple answer is, you cannot put arbitrary Python code on a single line. Some simple cases can be combined using `;`, but in general you *need* newlines. — chepner, Jan 30 '19 at 16:28

score 0 · Answer 1 · edited Mar 26 '19 at 05:58

As per my code update, the syntax bellow works :

#aws codecommit get-repository-triggers --repository-name $repository | python -c \
  'import json, sys, os; triggers = json.load(sys.stdin).get("triggers", []); fp = open(os.environ["triggersfile"], "r"); triggers_doc = json.load(fp); fp.close(); triggers_doc["triggers"].extend(triggers); triggers_doc["triggers"] = list({trigger["name"]:trigger for trigger in triggers_doc["triggers"]}.values()); fd = open(os.environ["triggersfile"], "w");json.dump(triggers_doc, fd, indent=4); fd.close()'

but I wanted to understand why with statement doesn't work here

With, If... statements in python inline code

1 Answers1