async exec in python
3
I'd like to call exec in an async function and do something like the following code (which is not valid):
import asyncio
async def f():
await exec('x = 1n' 'await asyncio.sleep(x)')
More precisely, I'd like to be able to wait for a future inside the code that runs in exec.
How can this be achieved?
python python-3.x exec python-asyncio
edited Jul 1 '17 at 14:03
falsetru
244k33423423
asked Jul 1 '17 at 9:01
jerry
1986
add a comment |
3
I'd like to call exec in an async function and do something like the following code (which is not valid):
import asyncio
async def f():
await exec('x = 1n' 'await asyncio.sleep(x)')
More precisely, I'd like to be able to wait for a future inside the code that runs in exec.
How can this be achieved?
python python-3.x exec python-asyncio
edited Jul 1 '17 at 14:03
falsetru
244k33423423
asked Jul 1 '17 at 9:01
jerry
1986
2
await eval('asyncio.sleep(1))
– falsetru
Jul 1 '17 at 14:01
I put x=1 on purpose because I really have to call exec and not eval.
– jerry
Jul 1 '17 at 18:12
2
How about this?await eval('asyncio.sleep(x)', globals(), {'x': 1})
– falsetru
Jul 2 '17 at 1:18
add a comment |
3
3
3
I'd like to call exec in an async function and do something like the following code (which is not valid):
import asyncio
async def f():
await exec('x = 1n' 'await asyncio.sleep(x)')
More precisely, I'd like to be able to wait for a future inside the code that runs in exec.
How can this be achieved?
python python-3.x exec python-asyncio
edited Jul 1 '17 at 14:03
falsetru
244k33423423
asked Jul 1 '17 at 9:01
jerry
1986
I'd like to call exec in an async function and do something like the following code (which is not valid):
import asyncio
async def f():
await exec('x = 1n' 'await asyncio.sleep(x)')
More precisely, I'd like to be able to wait for a future inside the code that runs in exec.
How can this be achieved?
python python-3.x exec python-asyncio
python python-3.x exec python-asyncio
edited Jul 1 '17 at 14:03
falsetru
244k33423423
asked Jul 1 '17 at 9:01
jerry
1986
edited Jul 1 '17 at 14:03
falsetru
244k33423423
asked Jul 1 '17 at 9:01
jerry
1986
edited Jul 1 '17 at 14:03
falsetru
244k33423423
edited Jul 1 '17 at 14:03
falsetru
244k33423423
edited Jul 1 '17 at 14:03
falsetru
244k33423423
244k33423423
asked Jul 1 '17 at 9:01
jerry
1986
asked Jul 1 '17 at 9:01
jerry
1986
asked Jul 1 '17 at 9:01
jerry
1986
1986
2
await eval('asyncio.sleep(1))
– falsetru
Jul 1 '17 at 14:01
I put x=1 on purpose because I really have to call exec and not eval.
– jerry
Jul 1 '17 at 18:12
2
How about this?await eval('asyncio.sleep(x)', globals(), {'x': 1})
– falsetru
Jul 2 '17 at 1:18
add a comment |
2
await eval('asyncio.sleep(1))
– falsetru
Jul 1 '17 at 14:01
I put x=1 on purpose because I really have to call exec and not eval.
– jerry
Jul 1 '17 at 18:12
2
How about this?await eval('asyncio.sleep(x)', globals(), {'x': 1})
– falsetru
Jul 2 '17 at 1:18
2
2
await eval('asyncio.sleep(1))– falsetru
Jul 1 '17 at 14:01
await eval('asyncio.sleep(1))– falsetru
Jul 1 '17 at 14:01
I put x=1 on purpose because I really have to call exec and not eval.
– jerry
Jul 1 '17 at 18:12
I put x=1 on purpose because I really have to call exec and not eval.
– jerry
Jul 1 '17 at 18:12
2
2
How about this?
await eval('asyncio.sleep(x)', globals(), {'x': 1})– falsetru
Jul 2 '17 at 1:18
How about this?
await eval('asyncio.sleep(x)', globals(), {'x': 1})– falsetru
Jul 2 '17 at 1:18
add a comment |
3 Answers
3
active
oldest
votes
1
Here's my solution. No libraries needed including asyncio. 😄
async def execute(code):
exec(
f'async def __ex(): ' +
''.join(f'n {l}' for l in code.split('n'))
)
return await locals()['__ex']()
answered Nov 12 '18 at 3:51
YouTwitFace
262
1
Welcome to Stack Overflow! Please try to provide a nice description about how your solution works. See: How do I write a good answer?. Thanks.
– Shree
Nov 12 '18 at 4:00
add a comment |
6
Yours problem is that you are trying to await to None object- exec ignores the return value from its code, and always returns None.
If you want to execute and await to the result you should use eval- eval returns the value of the given expression.
Your's code should look like this:
import asyncio
async def f():
exec('x = 1')
await eval('asyncio.sleep(x)')
loop = asyncio.get_event_loop()
loop.run_until_complete(f())
loop.close()
answered Jul 2 '17 at 8:16
Yuval Pruss
2,10431535
I wanted to do it without parsing the string in order to split "x = 1" and "asyncio.sleep(x)"
– jerry
Dec 5 '18 at 14:05
add a comment |
1
Thanks for all the suggestions. I figured out that this can be done with greenlets along async, since greenlets allow performing "top level await":
import greenlet
import asyncio
class GreenAwait:
def __init__(self, child):
self.current = greenlet.getcurrent()
self.value = None
self.child = child
def __call__(self, future):
self.value = future
self.current.switch()
def __iter__(self):
while self.value is not None:
yield self.value
self.value = None
self.child.switch()
def gexec(code):
child = greenlet.greenlet(exec)
gawait = GreenAwait(child)
child.switch(code, {'gawait': gawait})
yield from gawait
async def aexec(code):
green = greenlet.greenlet(gexec)
gen = green.switch(code)
for future in gen:
await future
# modified asyncio example from Python docs
CODE = ('import asyncion'
'import datetimen'
'async def display_date():n'
' for i in range(5):n'
' print(datetime.datetime.now())n'
' await asyncio.sleep(1)n')
def loop():
loop = asyncio.get_event_loop()
loop.run_until_complete(aexec(CODE + 'gawait(display_date())'))
loop.close()
answered Sep 7 '17 at 3:46
jerry
1986
1
Thank you! This is what I needed as well. Nice to know that others have the same problem.
– UnsignedByte
May 13 '18 at 20:21
add a comment |
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3 Answers
3
active
oldest
votes
3 Answers
3
active
oldest
votes
active
oldest
votes
active
oldest
votes
1
Here's my solution. No libraries needed including asyncio. 😄
async def execute(code):
exec(
f'async def __ex(): ' +
''.join(f'n {l}' for l in code.split('n'))
)
return await locals()['__ex']()
answered Nov 12 '18 at 3:51
YouTwitFace
262
1
Welcome to Stack Overflow! Please try to provide a nice description about how your solution works. See: How do I write a good answer?. Thanks.
– Shree
Nov 12 '18 at 4:00
add a comment |
1
Here's my solution. No libraries needed including asyncio. 😄
async def execute(code):
exec(
f'async def __ex(): ' +
''.join(f'n {l}' for l in code.split('n'))
)
return await locals()['__ex']()
answered Nov 12 '18 at 3:51
YouTwitFace
262
1
Welcome to Stack Overflow! Please try to provide a nice description about how your solution works. See: How do I write a good answer?. Thanks.
– Shree
Nov 12 '18 at 4:00
add a comment |
1
1
1
Here's my solution. No libraries needed including asyncio. 😄
async def execute(code):
exec(
f'async def __ex(): ' +
''.join(f'n {l}' for l in code.split('n'))
)
return await locals()['__ex']()
answered Nov 12 '18 at 3:51
YouTwitFace
262
Here's my solution. No libraries needed including asyncio. 😄
async def execute(code):
exec(
f'async def __ex(): ' +
''.join(f'n {l}' for l in code.split('n'))
)
return await locals()['__ex']()
answered Nov 12 '18 at 3:51
YouTwitFace
262
edited Nov 13 '18 at 4:19
answered Nov 12 '18 at 3:51
YouTwitFace
262
answered Nov 12 '18 at 3:51
YouTwitFace
262
answered Nov 12 '18 at 3:51
YouTwitFace
262
262
1
Welcome to Stack Overflow! Please try to provide a nice description about how your solution works. See: How do I write a good answer?. Thanks.
– Shree
Nov 12 '18 at 4:00
add a comment |
1
Welcome to Stack Overflow! Please try to provide a nice description about how your solution works. See: How do I write a good answer?. Thanks.
– Shree
Nov 12 '18 at 4:00
1
1
Welcome to Stack Overflow! Please try to provide a nice description about how your solution works. See: How do I write a good answer?. Thanks.
– Shree
Nov 12 '18 at 4:00
Welcome to Stack Overflow! Please try to provide a nice description about how your solution works. See: How do I write a good answer?. Thanks.
– Shree
Nov 12 '18 at 4:00
add a comment |
6
Yours problem is that you are trying to await to None object- exec ignores the return value from its code, and always returns None.
If you want to execute and await to the result you should use eval- eval returns the value of the given expression.
Your's code should look like this:
import asyncio
async def f():
exec('x = 1')
await eval('asyncio.sleep(x)')
loop = asyncio.get_event_loop()
loop.run_until_complete(f())
loop.close()
answered Jul 2 '17 at 8:16
Yuval Pruss
2,10431535
I wanted to do it without parsing the string in order to split "x = 1" and "asyncio.sleep(x)"
– jerry
Dec 5 '18 at 14:05
add a comment |
6
Yours problem is that you are trying to await to None object- exec ignores the return value from its code, and always returns None.
If you want to execute and await to the result you should use eval- eval returns the value of the given expression.
Your's code should look like this:
import asyncio
async def f():
exec('x = 1')
await eval('asyncio.sleep(x)')
loop = asyncio.get_event_loop()
loop.run_until_complete(f())
loop.close()
answered Jul 2 '17 at 8:16
Yuval Pruss
2,10431535
I wanted to do it without parsing the string in order to split "x = 1" and "asyncio.sleep(x)"
– jerry
Dec 5 '18 at 14:05
add a comment |
6
6
6
Yours problem is that you are trying to await to None object- exec ignores the return value from its code, and always returns None.
If you want to execute and await to the result you should use eval- eval returns the value of the given expression.
Your's code should look like this:
import asyncio
async def f():
exec('x = 1')
await eval('asyncio.sleep(x)')
loop = asyncio.get_event_loop()
loop.run_until_complete(f())
loop.close()
answered Jul 2 '17 at 8:16
Yuval Pruss
2,10431535
Yours problem is that you are trying to await to None object- exec ignores the return value from its code, and always returns None.
If you want to execute and await to the result you should use eval- eval returns the value of the given expression.
Your's code should look like this:
import asyncio
async def f():
exec('x = 1')
await eval('asyncio.sleep(x)')
loop = asyncio.get_event_loop()
loop.run_until_complete(f())
loop.close()
answered Jul 2 '17 at 8:16
Yuval Pruss
2,10431535
answered Jul 2 '17 at 8:16
Yuval Pruss
2,10431535
answered Jul 2 '17 at 8:16
Yuval Pruss
2,10431535
answered Jul 2 '17 at 8:16
Yuval Pruss
2,10431535
2,10431535
I wanted to do it without parsing the string in order to split "x = 1" and "asyncio.sleep(x)"
– jerry
Dec 5 '18 at 14:05
add a comment |
I wanted to do it without parsing the string in order to split "x = 1" and "asyncio.sleep(x)"
– jerry
Dec 5 '18 at 14:05
I wanted to do it without parsing the string in order to split "x = 1" and "asyncio.sleep(x)"
– jerry
Dec 5 '18 at 14:05
I wanted to do it without parsing the string in order to split "x = 1" and "asyncio.sleep(x)"
– jerry
Dec 5 '18 at 14:05
add a comment |
1
Thanks for all the suggestions. I figured out that this can be done with greenlets along async, since greenlets allow performing "top level await":
import greenlet
import asyncio
class GreenAwait:
def __init__(self, child):
self.current = greenlet.getcurrent()
self.value = None
self.child = child
def __call__(self, future):
self.value = future
self.current.switch()
def __iter__(self):
while self.value is not None:
yield self.value
self.value = None
self.child.switch()
def gexec(code):
child = greenlet.greenlet(exec)
gawait = GreenAwait(child)
child.switch(code, {'gawait': gawait})
yield from gawait
async def aexec(code):
green = greenlet.greenlet(gexec)
gen = green.switch(code)
for future in gen:
await future
# modified asyncio example from Python docs
CODE = ('import asyncion'
'import datetimen'
'async def display_date():n'
' for i in range(5):n'
' print(datetime.datetime.now())n'
' await asyncio.sleep(1)n')
def loop():
loop = asyncio.get_event_loop()
loop.run_until_complete(aexec(CODE + 'gawait(display_date())'))
loop.close()
answered Sep 7 '17 at 3:46
jerry
1986
1
Thank you! This is what I needed as well. Nice to know that others have the same problem.
– UnsignedByte
May 13 '18 at 20:21
add a comment |
1
Thanks for all the suggestions. I figured out that this can be done with greenlets along async, since greenlets allow performing "top level await":
import greenlet
import asyncio
class GreenAwait:
def __init__(self, child):
self.current = greenlet.getcurrent()
self.value = None
self.child = child
def __call__(self, future):
self.value = future
self.current.switch()
def __iter__(self):
while self.value is not None:
yield self.value
self.value = None
self.child.switch()
def gexec(code):
child = greenlet.greenlet(exec)
gawait = GreenAwait(child)
child.switch(code, {'gawait': gawait})
yield from gawait
async def aexec(code):
green = greenlet.greenlet(gexec)
gen = green.switch(code)
for future in gen:
await future
# modified asyncio example from Python docs
CODE = ('import asyncion'
'import datetimen'
'async def display_date():n'
' for i in range(5):n'
' print(datetime.datetime.now())n'
' await asyncio.sleep(1)n')
def loop():
loop = asyncio.get_event_loop()
loop.run_until_complete(aexec(CODE + 'gawait(display_date())'))
loop.close()
answered Sep 7 '17 at 3:46
jerry
1986
1
Thank you! This is what I needed as well. Nice to know that others have the same problem.
– UnsignedByte
May 13 '18 at 20:21
add a comment |
1
1
1
Thanks for all the suggestions. I figured out that this can be done with greenlets along async, since greenlets allow performing "top level await":
import greenlet
import asyncio
class GreenAwait:
def __init__(self, child):
self.current = greenlet.getcurrent()
self.value = None
self.child = child
def __call__(self, future):
self.value = future
self.current.switch()
def __iter__(self):
while self.value is not None:
yield self.value
self.value = None
self.child.switch()
def gexec(code):
child = greenlet.greenlet(exec)
gawait = GreenAwait(child)
child.switch(code, {'gawait': gawait})
yield from gawait
async def aexec(code):
green = greenlet.greenlet(gexec)
gen = green.switch(code)
for future in gen:
await future
# modified asyncio example from Python docs
CODE = ('import asyncion'
'import datetimen'
'async def display_date():n'
' for i in range(5):n'
' print(datetime.datetime.now())n'
' await asyncio.sleep(1)n')
def loop():
loop = asyncio.get_event_loop()
loop.run_until_complete(aexec(CODE + 'gawait(display_date())'))
loop.close()
answered Sep 7 '17 at 3:46
jerry
1986
Thanks for all the suggestions. I figured out that this can be done with greenlets along async, since greenlets allow performing "top level await":
import greenlet
import asyncio
class GreenAwait:
def __init__(self, child):
self.current = greenlet.getcurrent()
self.value = None
self.child = child
def __call__(self, future):
self.value = future
self.current.switch()
def __iter__(self):
while self.value is not None:
yield self.value
self.value = None
self.child.switch()
def gexec(code):
child = greenlet.greenlet(exec)
gawait = GreenAwait(child)
child.switch(code, {'gawait': gawait})
yield from gawait
async def aexec(code):
green = greenlet.greenlet(gexec)
gen = green.switch(code)
for future in gen:
await future
# modified asyncio example from Python docs
CODE = ('import asyncion'
'import datetimen'
'async def display_date():n'
' for i in range(5):n'
' print(datetime.datetime.now())n'
' await asyncio.sleep(1)n')
def loop():
loop = asyncio.get_event_loop()
loop.run_until_complete(aexec(CODE + 'gawait(display_date())'))
loop.close()
answered Sep 7 '17 at 3:46
jerry
1986
edited Sep 7 '17 at 3:52
answered Sep 7 '17 at 3:46
jerry
1986
answered Sep 7 '17 at 3:46
jerry
1986
answered Sep 7 '17 at 3:46
jerry
1986
1986
1
Thank you! This is what I needed as well. Nice to know that others have the same problem.
– UnsignedByte
May 13 '18 at 20:21
add a comment |
1
Thank you! This is what I needed as well. Nice to know that others have the same problem.
– UnsignedByte
May 13 '18 at 20:21
1
1
Thank you! This is what I needed as well. Nice to know that others have the same problem.
– UnsignedByte
May 13 '18 at 20:21
Thank you! This is what I needed as well. Nice to know that others have the same problem.
– UnsignedByte
May 13 '18 at 20:21
add a comment |
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2
await eval('asyncio.sleep(1))– falsetru
Jul 1 '17 at 14:01
I put x=1 on purpose because I really have to call exec and not eval.
– jerry
Jul 1 '17 at 18:12
2
How about this?
await eval('asyncio.sleep(x)', globals(), {'x': 1})– falsetru
Jul 2 '17 at 1:18