Passing Ipython variables as string arguments to shell command

Question

How do I execute a shell command from Ipython/Jupyter notebook passing the value of a python string variable as a string in the bash argument like in this example:

sp_name = 'littleGuy' #the variable

sp_details = !az ad app list --filter "DisplayName eq '$sp_name'" #the shell command

I've tried using $sp_name alone, ${sp_name}, {sp_name} etc as outlined in this related question, but none have worked.

The kicker here is the variable name needs to be quoted as a string in the shell command.

EDIT1:

@manu190466. I was judging from the string output that your solution worked. It appears for some reason it does not in practice. I wonder if az ad app list URL encodes the query or something...?

Thoughts?

manu190466 · Accepted Answer · 2020-05-09 16:28:03Z

14

+50

The main problem you encounters seems to come from the quotes needed in your string. You can keep the quotes in your string by using a format instruction and a raw string.

Use a 'r' before the whole string to indicate it is to be read as raw string, ie: special caracters have to not be interpreted. A raw string is not strictly required in your case because the string constructor of python is able to keep single quotes in a double quotes declaration but I think it's a good habit to use raw string declarators when there are non alphanumerics in it.

There are at least two way to format strings :

Older method herited from ancient langages with % symbols:

sp_name = 'littleGuy' #the variable
sp_query = r"DisplayName eq '%s'"%(sp_name) 

sp_details = !az ad app list --filter {sp_query}

Newer method with {} symbols and the format() method :

sp_name = 'littleGuy' #the variable
sp_query = r"DisplayName eq '{}'".format(sp_name) 

sp_details = !az ad app list --filter {sp_query}

edited May 9, 2020 at 16:28

answered May 9, 2020 at 16:14

manu190466

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2 Comments

SeaDude Over a year ago

This worked. Thank you. sp_query = r"DisplayName eq '{}'".format(sp_name), sp_query, "DisplayName eq 'python-sp'"

combinatorist Over a year ago

Is this supposed to work in the pure ipython shell (CLI, not the Jupyter notebook) as well? It didn't seem to for me, but maybe that's because I had some extra quoting in my case.

Ehsan · Accepted Answer · 2020-05-09 14:37:11Z

0

would you try something like this:

sp_name = 'littleGuy' #the variable
sp_query = "DisplayName eq "+sp_name 

sp_details = !az ad app list --filter {sp_query}

answered May 9, 2020 at 14:37

Ehsan

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3 Comments

SeaDude Over a year ago

Same error as before. The sp_name needs additional quotes within the DisplayName eq string. Should be "DisplayName eq 'littleGuy'".

sp_name = 'littleGuy' sp_query = "DisplayName eq " + sp_name sp_details = !az ad app list {sp_query} > sp_details2.json sp_details

['ERROR: az: error: unrecognized arguments: DisplayName eq littleGuy',  'usage: az [-h] [--verbose] [--debug]',  '          [--output {json,jsonc,table,tsv,yaml,none}] [--query JMESPATH]',  '          {ad} ...']

Ehsan Over a year ago

what if you add quotation to you sp_name? like "'littleGuy'"

SeaDude Over a year ago

Tried sp_name = "littleGuy", sp_name = "'littleGuy'" and sp_name = '"littleGuy"'. Same error result.

Tarun Lalwani · Accepted Answer · 2020-05-11 05:29:13Z

0

The issue can be also resolved using something like below

sp_name = 'littleGuy' #the variable
sp_details = !az ad app list --filter "DisplayName eq '{sp_name}'"

edited May 11, 2020 at 5:29

answered May 10, 2020 at 5:11

Tarun Lalwani

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6 Comments

SeaDude Over a year ago

Hm. I still receive an error on this one ERROR: az: error: unrecognized arguments: eq \'littleGuy\'"',

Tarun Lalwani Over a year ago

@SeaDude, can you comment what command you run when you are using a bash terminal

SeaDude Over a year ago

Sure. sp_name = 'littleGuy' sp_details = !az ad app list --filter \"DisplayName eq \'{sp_name}\'\" sp_details

Tarun Lalwani Over a year ago

Not this. Open a terminal and run the command in a bash and tell me what command you ran. Without iPython

SeaDude Over a year ago

IPython is the subject of this question as well as my only python env. I'm running terminal commands from IPython, with no alternatives, in this case.

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