<div dir="ltr">Ideally, the "next_depth" field would also not be defined, which may be easier to handle with the later syntax of putting an 'if' out in front.<br></div><br><div class="gmail_quote"><div dir="ltr" class="gmail_attr">On Fri, Apr 26, 2019 at 11:56 AM Sebastian Kreft <<a href="mailto:skreft@gmail.com">skreft@gmail.com</a>> wrote:<br></div><blockquote class="gmail_quote" style="margin:0px 0px 0px 0.8ex;border-left:1px solid rgb(204,204,204);padding-left:1ex"><div dir="ltr"><div dir="ltr"></div><br><div class="gmail_quote"><div dir="ltr" class="gmail_attr">On Fri, Apr 26, 2019 at 11:07 AM Joshua Marshall <<a href="mailto:j.marshall@arroyo.io" target="_blank">j.marshall@arroyo.io</a>> wrote:<br></div><blockquote class="gmail_quote" style="margin:0px 0px 0px 0.8ex;border-left:1px solid rgb(204,204,204);padding-left:1ex"><div dir="ltr"><div dir="ltr"><div dir="ltr"><div>Hello all,</div><div><br></div><div>I have a use case where I need to send a `dict` to a module as an argument. Inside of this, it has a multi-level structure, but each field I need to set may only be set to a single value. Fields must be valid, non-empty strings. It looks a lot like the following in my code:</div><div><br></div><div>```</div><div>def my_func(val_1, val_2):</div><div> return {</div><div> "field_1": val_1,</div><div> "next_depth": {</div><div> "field_2": val_2<br></div><div> }<br></div><div> }<br></div><div>```</div><div><br></div><div>What I want to do is:</div><div>```<div>def my_func(val_1, val_2):</div><div> return {</div><div> "field_1": val_1 if val_1,</div><div> "next_depth": {</div><div> "field_2": val_2 if val_2<br></div><div> }<br></div><div> }<br></div><div>```</div></div></div></div></div></blockquote><div>If val_2 here evaluates to falsey, will next_depth still be defined? From the code I would say that no. But your use case may require to not define the next_depth subdict without any values, as that may break the receiver expectations (think of JSON Schema). <br> </div><blockquote class="gmail_quote" style="margin:0px 0px 0px 0.8ex;border-left:1px solid rgb(204,204,204);padding-left:1ex"><div dir="ltr"><div dir="ltr"><div dir="ltr"><div><div><div><br></div><div>Or:</div><div>```<div>def my_func(val_1, val_2):</div><div> return {</div><div> if val_1 : "field_1": val_1,</div><div> "next_depth": {</div><div> if val_2: "field_2": val_2<br></div><div> }<br></div><div> }<br></div><div>```</div></div></div></div><div><br></div><div>Where each conditional in this context functions as:</div><div>```<br></div><div>if value:<br> d["your_key"] = value<br></div><div>```</div><div>for each conditionally added and set key.<br></div><div><br></div><div>From the slack channel #learning_python, there are a number of more general points which need to be handled. The more core syntax, which should be valid throughout the language, would be to have statements like `x = y if cond` and `x[y if cond]`. The first of these intuitively reorganizes to `if cond: x = y`, but the second is not as clear, with a likely equivalent of `if cond: x[y] else raise Exception`.</div><div><br></div><div>Thanks to Tom Forbes and Jim Kelly for helping critique the idea thus far.<br></div></div></div></div>
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</blockquote></div><br clear="all"><div><br></div>-- <br><div dir="ltr" class="gmail-m_4585799476456745986gmail_signature">Sebastian Kreft</div></div>
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