python function call syntax ... result = foo() ['abc']

Question

number = droid.readPhoneState()['result']['incomingNumber']

What are 'result' and 'incomingNumber' in this syntax -- are they not parameters?

How are they related to the function readPhoneState?

import android

droid = android.Android()
droid.startTrackingPhoneState()

number = droid.readPhoneState()['result']['incomingNumber']

if number != None:
  droid.speak('Call from '+str(number))
else:
  droid.makeToast('No incoming call')

You don't need to mark code sections like you did. Just indent by 4 spaces. — Johannes Charra, Nov 22 '10 at 14:42

score 9 · Accepted Answer · answered Nov 22 '10 at 14:41

9

droid.readPhoneState() returns a dict of dicts. Equivalent code:

outerDict = droid.readPhoneState()
innerDict = outerDict['result']
number = innerDict['incomingNumber']

answered Nov 22 '10 at 14:41

Aaron Digulla

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Thanks a lot, where is this syntax documented – Tiwari Nov 22 '10 at 14:47

score 2 · Answer 2 · answered Nov 22 '10 at 14:42

result and incomingNumber are keys to a dictionary or an instance of a class that implements method __getitem__. This means that readPhoneState() returns a dictionary object, which supposed to have a key result and the corresponding value is a dictionary object which supposed to have a key incomingNumber.

score 1 · Answer 3 · answered Nov 22 '10 at 14:43

1

the interpretation is that droid.readPhoneState() returns a dict, whose value corresponding to the key 'result' is another dict.

answered Nov 22 '10 at 14:43

lijie

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score 1 · Answer 4 · answered Nov 22 '10 at 14:44

1

readPhoneState() is the method and it returns a dictionary object.

The dictionary object contains the property result which is also a dictionary object containing the property incomingNumber

answered Nov 22 '10 at 14:44

John Giotta

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score 0 · Answer 5 · answered Nov 22 '10 at 14:43

0

Supposedly, readPhoneState() returns a dictionary where values are, again, dictionaries.

With this syntax, you get the dictionary - returned by readPhoneState() - associated with key 'result' and ask it for the value whose key is 'incomingNumber'.

answered Nov 22 '10 at 14:43

Simone

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python function call syntax ... result = foo() ['abc']

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