for循环内的睡眠问题
Issue with sleep inside for loop
我的 python 代码中有一个条件，如果满足条件，它应该发送电子邮件。当再次执行相同的条件时，它应该等待 60 分钟才能发送另一封电子邮件。我在 for 循环中使用了 if，但问题是 for 循环中的其他行由于内部的 if 循环而被卡住。我该如何克服这个问题？
def send_email(previousindex,index):
if previousindex!= index or previousindex is None:
print('email sent')
else:
print('Wait for 1 hr')
time.sleep(3600)
while True:
previousindex = None
for index in df.index: # row in df.iterrows():
if df.loc[index, 'Time flag'] == 1:
print('fail')
print(previousindex)
send_email(previousindex,index)
previousindex = index
else:
time.sleep(10)
continue
time.sleep(10)
def send_email(previous_index, index):
if index not in previous_index:
print('email sent')
else:
print(previous_index)
print('Wait for 1 hr')
time.sleep(3500)
previous_index.clear()
print('email sent')
while True:
df = pd.read_csv(r'C:/Users/KrishnamurthyKA/Desktop/Project/Test.csv',sep = ',')
for index in df.index: # row in df.iterrows():
if df.loc[index, 'Time flag'] == 1:
print('pass')
send_email(previous_index, index)
previous_index.append(index)
print(previous_index)
# if previousindex == index:
# print('entered if loop')
# print(previousindex)
# time.sleep(10)
else:
time.sleep(10)
continue
print(previous_index)
time.sleep(10)
编辑 2：
min = 2
while True:
for index in df.index:
now = datetime.datetime.now()
if df.loc[index,'Time flag'] == 1 and df.loc[df.index[index], "Last_email_sent"] == None:
print('pass')
df.loc[df.index[index], "Last_email_sent"] = now
print(now)
#send_email(index)
elif df.loc[index, 'Time flag'] == 1 and minutes < min:
print('wait')
print(minutes)
print(df.loc[index,'Last_email_sent'])
elif df.loc[index, 'Time flag'] == 1 and minutes >= min:
#send_email(index)
print('sending email after 1 min')
df.loc[index, "Last_email_sent"] = now
print(minutes)
minutes = divmod((now - df.loc[index, "Last_email_sent"]).total_seconds(), 60)[0]
else:
print('false')
time.sleep(10)
首先，你的逻辑可以简化为：
while True:
previous_index = None
for index in idx:
# First iteration
if condition(index) and previous_index is None:
send_email()
previous_index = index
elif condition(index) and previous_index != index:
send_email()
previous_index = index
elif condition(index) and previous_index == index:
# Wait 1 hour
time.sleep(3600)
else:
time.sleep(10) # Wait a bit
continue
根据我的解释，您会卡住，因为每次进入 time.sleep(3600) 时进程都会停止 1 小时。因此，在此期间，您希望循环的其余部分将 运行 保留在其他索引上。
问题是 time.sleep() 在指定的时间内暂停了打开的 python 进程。克服这个问题的一种方法是打开一个额外的进程来发送电子邮件。代码如下所示：
def send_email(previous_index, index):
if previous_index != index or previous_index is None:
# Send the e-mail
else:
# Wait 1 hour
time.sleep(3600)
# Send the e-mail
while True:
previous_index = None
for index in idx:
if condition(index):
Open_process(target = send_email, args = (previous_index, index))
previous_index = index
else:
time.sleep(10) # Wait a bit
continue
进程的缺点是打开有点慢。线程可能会更好，但是，因为您在每个循环之间包含 10 秒的睡眠，我认为这在这个应用程序中并不重要。
最后可以看看库multiprocessing来管理进程。
编辑：
def send_email(index):
# Function sending the e-mail
print ("e-mail sent")
# Each index is unique and the loop is executed every 10 s
# Key: index; Value: number of iterations; 360 iterations = 1 hour.
tracking = dict()
# Initialize with None
for index in df.index:
tracking[index] = None
while True:
for index in df.index:
if df.loc[index, 'Time flag'] == 1 and tracking[index] is None:
send_email(index)
tracking[index] = 1
elif df.loc[index, 'Time flag'] == 1 and tracking[index] < 360:
tracking[index] += 1
elif df.loc[index, 'Time flag'] == 1 and tracking[index] == 360:
send_email(index)
tracking[index] = 1 # Reset since an e-mail is sent.
else:
# df.loc[index, 'Time flag'] == 0
tracking[index] = None
time.sleep(10)
编辑 2
def send_email(index):
# Function sending the e-mail
print ("e-mail sent")
# Add column to keep tack of last e-mail send timing
# If the e-mail has never been sent, initialize to Nan, None, or -1
# No idea what is more convenient, but adapt the first if accordingly
df.add_column("Last e-mail sent timing")
while True:
for index in df.index:
if df.loc[index, 'Time flag'] == 1 and df[index, "Last e-mail sent timing"] is None:
send_email(index)
df[index, "Last e-mail sent timing"] = current.time()
elif df.loc[index, 'Time flag'] == 1 and current.time - df[index, "Last e-mail sent timing"] < 1 hour:
# skip
continue
elif df.loc[index, 'Time flag'] == 1 and current.time - df[index, "Last e-mail sent timing"] >= 1 hour:
send_email(index)
df[index, "Last e-mail sent timing"] = current.time()
time.sleep(10)
编辑 3：
duration_to_wait = 2 # in MINUTES
while True:
for index in df.index:
if df.loc[index,'Time flag'] == 1 and df.loc[df.index[index], "Last_email_sent"] == None:
send_email(index)
df.loc[df.index[index], "Last_email_sent"] = datetime.datetime.now()
elif df.loc[index, 'Time flag'] == 1 and datetime.datetime.now() - df.loc[df.index[index], "Last_email_sent"] < datetime.timedelta(minutes=duration_to_wait):
print('Wait')
print(datetime.datetime.now() - df.loc[df.index[index], "Last_email_sent"])
elif df.loc[index, 'Time flag'] == 1 and datetime.datetime.now() - df.loc[df.index[index], "Last_email_sent"] >= datetime.timedelta(minutes=duration_to_wait):
send_email(index)
df.loc[index, "Last_email_sent"] = datetime.datetime.now()
else:
print('false')
time.sleep(10)
我的 python 代码中有一个条件，如果满足条件，它应该发送电子邮件。当再次执行相同的条件时，它应该等待 60 分钟才能发送另一封电子邮件。我在 for 循环中使用了 if，但问题是 for 循环中的其他行由于内部的 if 循环而被卡住。我该如何克服这个问题？
def send_email(previousindex,index):
if previousindex!= index or previousindex is None:
print('email sent')
else:
print('Wait for 1 hr')
time.sleep(3600)
while True:
previousindex = None
for index in df.index: # row in df.iterrows():
if df.loc[index, 'Time flag'] == 1:
print('fail')
print(previousindex)
send_email(previousindex,index)
previousindex = index
else:
time.sleep(10)
continue
time.sleep(10)
def send_email(previous_index, index):
if index not in previous_index:
print('email sent')
else:
print(previous_index)
print('Wait for 1 hr')
time.sleep(3500)
previous_index.clear()
print('email sent')
while True:
df = pd.read_csv(r'C:/Users/KrishnamurthyKA/Desktop/Project/Test.csv',sep = ',')
for index in df.index: # row in df.iterrows():
if df.loc[index, 'Time flag'] == 1:
print('pass')
send_email(previous_index, index)
previous_index.append(index)
print(previous_index)
# if previousindex == index:
# print('entered if loop')
# print(previousindex)
# time.sleep(10)
else:
time.sleep(10)
continue
print(previous_index)
time.sleep(10)
编辑 2：
min = 2
while True:
for index in df.index:
now = datetime.datetime.now()
if df.loc[index,'Time flag'] == 1 and df.loc[df.index[index], "Last_email_sent"] == None:
print('pass')
df.loc[df.index[index], "Last_email_sent"] = now
print(now)
#send_email(index)
elif df.loc[index, 'Time flag'] == 1 and minutes < min:
print('wait')
print(minutes)
print(df.loc[index,'Last_email_sent'])
elif df.loc[index, 'Time flag'] == 1 and minutes >= min:
#send_email(index)
print('sending email after 1 min')
df.loc[index, "Last_email_sent"] = now
print(minutes)
minutes = divmod((now - df.loc[index, "Last_email_sent"]).total_seconds(), 60)[0]
else:
print('false')
time.sleep(10)
首先，你的逻辑可以简化为：
while True:
previous_index = None
for index in idx:
# First iteration
if condition(index) and previous_index is None:
send_email()
previous_index = index
elif condition(index) and previous_index != index:
send_email()
previous_index = index
elif condition(index) and previous_index == index:
# Wait 1 hour
time.sleep(3600)
else:
time.sleep(10) # Wait a bit
continue
根据我的解释，您会卡住，因为每次进入 time.sleep(3600) 时进程都会停止 1 小时。因此，在此期间，您希望循环的其余部分将 运行 保留在其他索引上。
问题是 time.sleep() 在指定的时间内暂停了打开的 python 进程。克服这个问题的一种方法是打开一个额外的进程来发送电子邮件。代码如下所示：
def send_email(previous_index, index):
if previous_index != index or previous_index is None:
# Send the e-mail
else:
# Wait 1 hour
time.sleep(3600)
# Send the e-mail
while True:
previous_index = None
for index in idx:
if condition(index):
Open_process(target = send_email, args = (previous_index, index))
previous_index = index
else:
time.sleep(10) # Wait a bit
continue
进程的缺点是打开有点慢。线程可能会更好，但是，因为您在每个循环之间包含 10 秒的睡眠，我认为这在这个应用程序中并不重要。
最后可以看看库multiprocessing来管理进程。
编辑：
def send_email(index):
# Function sending the e-mail
print ("e-mail sent")
# Each index is unique and the loop is executed every 10 s
# Key: index; Value: number of iterations; 360 iterations = 1 hour.
tracking = dict()
# Initialize with None
for index in df.index:
tracking[index] = None
while True:
for index in df.index:
if df.loc[index, 'Time flag'] == 1 and tracking[index] is None:
send_email(index)
tracking[index] = 1
elif df.loc[index, 'Time flag'] == 1 and tracking[index] < 360:
tracking[index] += 1
elif df.loc[index, 'Time flag'] == 1 and tracking[index] == 360:
send_email(index)
tracking[index] = 1 # Reset since an e-mail is sent.
else:
# df.loc[index, 'Time flag'] == 0
tracking[index] = None
time.sleep(10)
编辑 2
def send_email(index):
# Function sending the e-mail
print ("e-mail sent")
# Add column to keep tack of last e-mail send timing
# If the e-mail has never been sent, initialize to Nan, None, or -1
# No idea what is more convenient, but adapt the first if accordingly
df.add_column("Last e-mail sent timing")
while True:
for index in df.index:
if df.loc[index, 'Time flag'] == 1 and df[index, "Last e-mail sent timing"] is None:
send_email(index)
df[index, "Last e-mail sent timing"] = current.time()
elif df.loc[index, 'Time flag'] == 1 and current.time - df[index, "Last e-mail sent timing"] < 1 hour:
# skip
continue
elif df.loc[index, 'Time flag'] == 1 and current.time - df[index, "Last e-mail sent timing"] >= 1 hour:
send_email(index)
df[index, "Last e-mail sent timing"] = current.time()
time.sleep(10)
编辑 3：
duration_to_wait = 2 # in MINUTES
while True:
for index in df.index:
if df.loc[index,'Time flag'] == 1 and df.loc[df.index[index], "Last_email_sent"] == None:
send_email(index)
df.loc[df.index[index], "Last_email_sent"] = datetime.datetime.now()
elif df.loc[index, 'Time flag'] == 1 and datetime.datetime.now() - df.loc[df.index[index], "Last_email_sent"] < datetime.timedelta(minutes=duration_to_wait):
print('Wait')
print(datetime.datetime.now() - df.loc[df.index[index], "Last_email_sent"])
elif df.loc[index, 'Time flag'] == 1 and datetime.datetime.now() - df.loc[df.index[index], "Last_email_sent"] >= datetime.timedelta(minutes=duration_to_wait):
send_email(index)
df.loc[index, "Last_email_sent"] = datetime.datetime.now()
else:
print('false')
time.sleep(10)