blocks|key|4661603|text|一个简单的实现可以是：|type|unstyled|depth|inlineStyleRanges|entityRanges|data|4661604|import+os.path
import+time

while+not+os.path.exists(file_path):
++++time.sleep(1)

if+os.path.isfile(file_path):
++++#+read+file
else:
++++raise+ValueError("%25s+isn't+a+file!"+%25+file_path)|code-block|syntax|javascript|4661605|您在每次检查后等待一定的时间，然后在路径存在时读取文件。如果从未创建过该文件，则可以停止该脚本，但会出现KeyboardInterruption异常。您还应该检查该路径是否为之后的文件，以避免某些不必要的异常。|offset|length|style|CODE|4661606|entityMap^0|0|0|1G|K|0^^$0|@$1|2|3|4|5|6|7|O|8|@]|9|@]|A|$]]|$1|B|3|C|5|D|7|P|8|@]|9|@]|A|$E|F]]|$1|G|3|H|5|6|7|Q|8|@$I|R|J|S|K|L]]|9|@]|A|$]]|$1|M|3|-4|5|6|7|T|8|@]|9|@]|A|$]]]|N|$]]

A simple implementation could be:

<pre><code>import os.path
import time

while not os.path.exists(file_path):
 time.sleep(1)

if os.path.isfile(file_path):
 # read file
else:
 raise ValueError("%s isn't a file!" % file_path)
</code></pre>

You wait a certain amount of time after each check, and then read the file when the path exists. The script can be stopped with the <code>KeyboardInterruption</code> exception if the file is never created. You should also check if the path is a file after, to avoid some unwanted exceptions.

blocks|key|155370|text|import+os
import+time
file_path="AIMP2.lnk"
if++os.path.lexists(file_path):
++++time.sleep(1)
++++if+os.path.isfile(file_path):
++++++++fob=open(file_path,'r');
++++++++read=fob.readlines();
++++++++for+i+in+read:
++++++++++++print+i
++++else:
++++++++print+"Selected+path+is+not+file"
else:
++++print+"File+not+Found+"%2Bfile_path|type|code-block|depth|inlineStyleRanges|entityRanges|data|syntax|javascript|155371|unstyled|entityMap^0|0^^$0|@$1|2|3|4|5|6|7|G|8|@]|9|@]|A|$B|C]]|$1|D|3|-4|5|E|7|H|8|@]|9|@]|A|$]]]|F|$]]

<pre><code>import os
import time
file_path="AIMP2.lnk"
if os.path.lexists(file_path):
 time.sleep(1)
 if os.path.isfile(file_path):
 fob=open(file_path,'r');
 read=fob.readlines();
 for i in read:
 print i
 else:
 print "Selected path is not file"
else:
 print "File not Found "+file_path
</code></pre>

blocks|key|155383|text|此代码可以按文件大小检查下载。|type|unstyled|depth|inlineStyleRanges|entityRanges|data|155384|import+os,+sys
import+time

def+getSize(filename):
++++if+os.path.isfile(filename):+
++++++++st+=+os.stat(filename)
++++++++return+st.st_size
++++else:
++++++++return+-1

def+wait_download(file_path):
++++current_size+=+getSize(file_path)
++++print("File+size")
++++time.sleep(1)
++++while+current_size+!=getSize(file_path)+or+getSize(file_path)==0:
++++++++current_size+=getSize(file_path)
++++++++print("current_size:"%2Bstr(current_size))
++++++++time.sleep(1)#+wait+download
++++print("Downloaded")|code-block|syntax|javascript|155385|entityMap^0|0|0^^$0|@$1|2|3|4|5|6|7|I|8|@]|9|@]|A|$]]|$1|B|3|C|5|D|7|J|8|@]|9|@]|A|$E|F]]|$1|G|3|-4|5|6|7|K|8|@]|9|@]|A|$]]]|H|$]]

This code can check download by file size.

<pre><code>import os, sys
import time

def getSize(filename):
 if os.path.isfile(filename): 
 st = os.stat(filename)
 return st.st_size
 else:
 return -1

def wait_download(file_path):
 current_size = getSize(file_path)
 print("File size")
 time.sleep(1)
 while current_size !=getSize(file_path) or getSize(file_path)==0:
 current_size =getSize(file_path)
 print("current_size:"+str(current_size))
 time.sleep(1)# wait download
 print("Downloaded")
</code></pre>

blocks|key|4661666|text|以下脚本将在下载文件或创建file_path后立即中断，否则在中断之前将等待文件下载或创建file_path的时间长达10秒。|type|unstyled|depth|inlineStyleRanges|entityRanges|data|4661667|import+os
import+time

time_to_wait+=+10
time_counter+=+0
while+not+os.path.exists(file_path):
++++time.sleep(1)
++++time_counter+%2B=+1
++++if+time_counter+>+time_to_wait:break

print("done")|code-block|syntax|javascript|4661668|entityMap^0|0|0^^$0|@$1|2|3|4|5|6|7|I|8|@]|9|@]|A|$]]|$1|B|3|C|5|D|7|J|8|@]|9|@]|A|$E|F]]|$1|G|3|-4|5|6|7|K|8|@]|9|@]|A|$]]]|H|$]]

The following script will break as soon as the file is dowloaded or the file_path is created otherwise it will wait upto 10 seconds for the file to be downloaded or the file_path to be created before breaking.

<pre><code>import os
import time

time_to_wait = 10
time_counter = 0
while not os.path.exists(file_path):
 time.sleep(1)
 time_counter += 1
 if time_counter &gt; time_to_wait:break

print("done")
</code></pre>

blocks|key|155430|text|import+os.path
import+time

file_present+=+False

while+file_present+=+False:
++++if+os.path.isfile(file_path):
+++++++#+read+file+in
+++++++file_present+=+True
+++++++break

++++time.sleep(5)|type|code-block|depth|inlineStyleRanges|entityRanges|data|syntax|javascript|155431|unstyled|entityMap^0|0^^$0|@$1|2|3|4|5|6|7|G|8|@]|9|@]|A|$B|C]]|$1|D|3|-4|5|E|7|H|8|@]|9|@]|A|$]]]|F|$]]

<pre><code>import os.path
import time

file_present = False

while file_present = False:
 if os.path.isfile(file_path):
 # read file in
 file_present = True
 break

 time.sleep(5)
 
</code></pre>

I need to wait until a file is created then read it in. I have the below code, but sure it does not work:

<pre><code>import os.path
if os.path.isfile(file_path):
 read file in
else:
 wait
</code></pre>

Any ideas please?

Check and wait until a file exists to read it

我需要等待一个文件被创建，然后读入它。我有下面的代码，但确定它不能工作：import os.pathif os.path.isfile(file_path):    read file inelse:    wait有什么想法吗？

问检查并等待，直到文件存在，才能读取它
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