Python: Print only one time inside a loop

2024/10/9 9:14:28

I have a code where I want capture a video from a camera. I want to use Logging library of Python to get messages on the shell or export them to a text file.

Here is a part of my code where inside the while loop I want to print Camera Opened Successfully

import numpy as np
import cv2
import logging as logcap = cv2.VideoCapture('5.mpg')while True:ret, image = cap.read()if ret == True:log.warning('Camera Opened Successfully')gray = cv2.cvtColor(image, cv2.COLOR_BGR2GRAY)clahe = cv2.createCLAHE(clipLimit = 15.0, tileGridSize=(8,8))gray1 = clahe.apply(gray)

but what I get in the shell is this:

until I terminated the running script. Any idea on how to make it print only once.

Answer
import numpy as np
import cv2
import logging as logcap = cv2.VideoCapture('5.mpg')
hasOpened = Falsewhile True:ret, image = cap.read()if ret and not hasOpened:log.warning('Camera Opened Successfully')hasOpened = True

If you want to break out of the loop after printing, follow Matt's answer. This option will continue in the loop and only print once.

https://en.xdnf.cn/q/70034.html

Related Q&A

Calling Different Functions in Python Based on Values in a List

I have a script that takes a list of metrics as an input, and then fetches those metrics from the database to perform various operations with them. My problem is that different clients get different s…

takes 1 positional argument but 2 were given

I would like to run a command line tool to run in a separate function and passed to the button click the additional command for this program but each time I get this as a response.takes 1 positional ar…

With py.test, database is not reset after LiveServerTestCase

I have a number of Django tests and typically run them using py.test. I recently added a new test case in a new file test_selenium.py. This Test Case has uses the LiveServerTestCase and StaticLiveSer…

Using flask wtforms validators without using a form

Im receiving user registration data from an iOS application and Id like to use the validators that come with wtforms to make sure the email and password are acceptable. However, Im not using a flask f…

How to install graph-tool for Anaconda Python 3.5 on linux-64?

Im trying to install graph-tool for Anaconda Python 3.5 on Ubuntu 14.04 (x64), but it turns out thats a real trick.I tried this approach, but run into the problem:The following specifications were foun…

How to quickly encrypt a password string in Django without an User Model?

Based on my current Django app settings, is there a function or a snippet that allows me to view the encrypted password, given a raw string? I am testing some functionality and this would be useful fo…

Embedding multiple gridspec layouts on a single matplotlib figure?

I am using the python graphing library matplotlib to graph several things in a report, and I found myself needing to have several fixed-count graphs above an arbitrary grid of smaller graphs. I search…

Writing integers in binary to file in python

How can I write integers to a file in binary in Python 3?For example, I want to write 6277101735386680763835789423176059013767194773182842284081 to a file in binary in exactly 24 bytes (unsigned, I wi…

Dropping some columns when using to_csv in pandas

I have a data frame which I want to write to tow files, one that contains all of the columns and one that has only a subset of the columns So for this data frame: Out_dataOut[9]: A B …

Setting Max Results in API v4 (python)

In v3 of the API Im seeing that there was a max-results parameter that could be passed to get more than 1000 records. I havent been able to figure out how to pass that parameter in v4 of the API using …