Can Flask support an optional parameter in a POST request?
In the application, the user has a choice to upload a picture or not. But
picture_url = request.files['image']
seems to cause the page to stop loading the request if no such file exists. Is there any way to make this optional?
Thanks
python post flask
asked Jul 2 '14 at 18:22
UtsavShahUtsavShah
617615
add a comment |
In the application, the user has a choice to upload a picture or not. But
picture_url = request.files['image']
seems to cause the page to stop loading the request if no such file exists. Is there any way to make this optional?
Thanks
python post flask
asked Jul 2 '14 at 18:22
UtsavShahUtsavShah
617615
add a comment |
In the application, the user has a choice to upload a picture or not. But
picture_url = request.files['image']
seems to cause the page to stop loading the request if no such file exists. Is there any way to make this optional?
Thanks
python post flask
asked Jul 2 '14 at 18:22
UtsavShahUtsavShah
617615
In the application, the user has a choice to upload a picture or not. But
picture_url = request.files['image']
seems to cause the page to stop loading the request if no such file exists. Is there any way to make this optional?
Thanks
python post flask
python post flask
asked Jul 2 '14 at 18:22
UtsavShahUtsavShah
617615
asked Jul 2 '14 at 18:22
UtsavShahUtsavShah
617615
asked Jul 2 '14 at 18:22
UtsavShahUtsavShah
617615
asked Jul 2 '14 at 18:22
UtsavShahUtsavShah
617615
asked Jul 2 '14 at 18:22
UtsavShahUtsavShah
617615
617615
add a comment |
add a comment |
1 Answer
1
active
oldest
votes
You are using syntax that throws an exception if the key is not present. Use .get() instead:
picture_url = request.files.get('image')
This returns None if the key was not set, e.g. no image field is present in the POST.
You could also handle the KeyError exception:
try:
picture_url = request.files['image']
except KeyError:
# no picture uploaded, do something else perhaps
answered Jul 2 '14 at 18:24
Martijn Pieters♦Martijn Pieters
711k13724812301
Just a quick question. This might seem stupid but what is the scope of the picture_url in the second example? Will it be available to the entire function? Considering without the try it is inside the function body
– UtsavShah
Jul 2 '14 at 18:31
@UtsavShah: it'll be available if no exception was thrown, in the rest of the function. You'd have to bind it in the exception handler too, or set a default before thetry. In this regard it is no different from binding a name in aifhandler.
– Martijn Pieters♦
Jul 2 '14 at 18:36
add a comment |
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1 Answer
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1 Answer
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You are using syntax that throws an exception if the key is not present. Use .get() instead:
picture_url = request.files.get('image')
This returns None if the key was not set, e.g. no image field is present in the POST.
You could also handle the KeyError exception:
try:
picture_url = request.files['image']
except KeyError:
# no picture uploaded, do something else perhaps
answered Jul 2 '14 at 18:24
Martijn Pieters♦Martijn Pieters
711k13724812301
Just a quick question. This might seem stupid but what is the scope of the picture_url in the second example? Will it be available to the entire function? Considering without the try it is inside the function body
– UtsavShah
Jul 2 '14 at 18:31
@UtsavShah: it'll be available if no exception was thrown, in the rest of the function. You'd have to bind it in the exception handler too, or set a default before thetry. In this regard it is no different from binding a name in aifhandler.
– Martijn Pieters♦
Jul 2 '14 at 18:36
add a comment |
You are using syntax that throws an exception if the key is not present. Use .get() instead:
picture_url = request.files.get('image')
This returns None if the key was not set, e.g. no image field is present in the POST.
You could also handle the KeyError exception:
try:
picture_url = request.files['image']
except KeyError:
# no picture uploaded, do something else perhaps
answered Jul 2 '14 at 18:24
Martijn Pieters♦Martijn Pieters
711k13724812301
Just a quick question. This might seem stupid but what is the scope of the picture_url in the second example? Will it be available to the entire function? Considering without the try it is inside the function body
– UtsavShah
Jul 2 '14 at 18:31
@UtsavShah: it'll be available if no exception was thrown, in the rest of the function. You'd have to bind it in the exception handler too, or set a default before thetry. In this regard it is no different from binding a name in aifhandler.
– Martijn Pieters♦
Jul 2 '14 at 18:36
add a comment |
You are using syntax that throws an exception if the key is not present. Use .get() instead:
picture_url = request.files.get('image')
This returns None if the key was not set, e.g. no image field is present in the POST.
You could also handle the KeyError exception:
try:
picture_url = request.files['image']
except KeyError:
# no picture uploaded, do something else perhaps
answered Jul 2 '14 at 18:24
Martijn Pieters♦Martijn Pieters
711k13724812301
You are using syntax that throws an exception if the key is not present. Use .get() instead:
picture_url = request.files.get('image')
This returns None if the key was not set, e.g. no image field is present in the POST.
You could also handle the KeyError exception:
try:
picture_url = request.files['image']
except KeyError:
# no picture uploaded, do something else perhaps
answered Jul 2 '14 at 18:24
Martijn Pieters♦Martijn Pieters
711k13724812301
answered Jul 2 '14 at 18:24
Martijn Pieters♦Martijn Pieters
711k13724812301
answered Jul 2 '14 at 18:24
Martijn Pieters♦Martijn Pieters
711k13724812301
answered Jul 2 '14 at 18:24
Martijn Pieters♦Martijn Pieters
711k13724812301
711k13724812301
Just a quick question. This might seem stupid but what is the scope of the picture_url in the second example? Will it be available to the entire function? Considering without the try it is inside the function body
– UtsavShah
Jul 2 '14 at 18:31
@UtsavShah: it'll be available if no exception was thrown, in the rest of the function. You'd have to bind it in the exception handler too, or set a default before thetry. In this regard it is no different from binding a name in aifhandler.
– Martijn Pieters♦
Jul 2 '14 at 18:36
add a comment |
Just a quick question. This might seem stupid but what is the scope of the picture_url in the second example? Will it be available to the entire function? Considering without the try it is inside the function body
– UtsavShah
Jul 2 '14 at 18:31
@UtsavShah: it'll be available if no exception was thrown, in the rest of the function. You'd have to bind it in the exception handler too, or set a default before thetry. In this regard it is no different from binding a name in aifhandler.
– Martijn Pieters♦
Jul 2 '14 at 18:36
Just a quick question. This might seem stupid but what is the scope of the picture_url in the second example? Will it be available to the entire function? Considering without the try it is inside the function body
– UtsavShah
Jul 2 '14 at 18:31
Just a quick question. This might seem stupid but what is the scope of the picture_url in the second example? Will it be available to the entire function? Considering without the try it is inside the function body
– UtsavShah
Jul 2 '14 at 18:31
@UtsavShah: it'll be available if no exception was thrown, in the rest of the function. You'd have to bind it in the exception handler too, or set a default before the
try. In this regard it is no different from binding a name in a if handler.– Martijn Pieters♦
Jul 2 '14 at 18:36
@UtsavShah: it'll be available if no exception was thrown, in the rest of the function. You'd have to bind it in the exception handler too, or set a default before the
try. In this regard it is no different from binding a name in a if handler.– Martijn Pieters♦
Jul 2 '14 at 18:36
add a comment |
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