The output in wrapped function isn't printed between decorator

Question

I don't know why the output in wrapped function hasn't been printed among decorator, my codes as below:

from functools import wraps
checkresultfile = './checkres1.log'
def log_detection_res(detect_items=''):
    def process_reminder_decorator(check_func):
        @wraps(check_func)
        def addingReminder(*args, **kwargs):
            process_begin_reminder = "=" * 10 + detect_items + "begin" + "=" * 10
            process_stop_reminder = "=" * 10 + detect_items + "end" + "=" * 10
            with open(checkresultfile, 'a') as res_file:
                res_file.write(process_begin_reminder + '\n')
                check_func(*args, **kwargs)
                res_file.write(process_stop_reminder + '\n')
            return check_func
        return addingReminder
    return process_reminder_decorator

@log_detection_res(detect_items='srlg conflict detection')
def relay_srlg_conflict_detect():
    tplt = "{0:^30}\t{1:^20}\t{2:^20}\t{3:^10}\t{4:^20}\t{5:^20}\t{6:^20}\t{7:^20}\t{8:^10}"
    output_file.write(
        tplt.format("Conflict_Index", "INGRESS", "EGRESS", "Index", "Fault_Node", "Fault_link", "Router_Node",
                    "Route_link", "SRLG") + "\n")

with open(checkresultfile, 'a') as output_file:
    relay_srlg_conflict_detect()

The output in file is:

==========srlg conflict detection begin==========
==========srlg conflict detection end==========
        Conflict_Index                INGRESS                  EGRESS             Index          Fault_Node              Fault_link             Router_Node              Route_link            SRLG  

what I am expecting is:

==========srlg conflict detection begin==========
  Conflict_Index                  INGRESS                  EGRESS             Index          Fault_Node              Fault_link             Router_Node              Route_link            SRLG  
==========srlg conflict detection end==========

Answer 1

your problem is that you are trying to open on the same time the same file

#!/usr/bin/env python
# -*- coding: utf-8 -*-
import time

from functools import wraps

checkresultfile = './checkres1.log'


def log_detection_res(detect_items=''):
    def process_reminder_decorator(check_func):
        @wraps(check_func)
        def addingReminder(*args, **kwargs):
            process_begin_reminder = "=" * 10 + detect_items + "begin" + "=" * 10
            process_stop_reminder = "=" * 10 + detect_items + "end" + "=" * 10
            with open(checkresultfile, 'a') as res_file:
                res_file.write(process_begin_reminder + '\n')
                check_func(output_file=res_file, *args, **kwargs)
                res_file.write(process_stop_reminder + '\n')
            return check_func

        return addingReminder

    return process_reminder_decorator


@log_detection_res(detect_items='srlg conflict detection')
def relay_srlg_conflict_detect(output_file):
    tplt = "{0:^30}\t{1:^20}\t{2:^20}\t{3:^10}\t{4:^20}\t{5:^20}\t{6:^20}\t{7:^20}\t{8:^10}"
    output_file.write(
        tplt.format("Conflict_Index", "INGRESS", "EGRESS", "Index", "Fault_Node", "Fault_link", "Router_Node",
                    "Route_link", "SRLG") + "\n")


relay_srlg_conflict_detect()

output

==========srlg conflict detectionbegin==========
        Conflict_Index                INGRESS                  EGRESS             Index          Fault_Node              Fault_link             Router_Node              Route_link            SRLG   
==========srlg conflict detectionend==========

Answer 2

The order you open the file is wrong.

Try this:

from functools import wraps

checkresultfile = './checkres1.log'


def log_detection_res(detect_items=''):
    def process_reminder_decorator(check_func):
        @wraps(check_func)
        def addingReminder(*args, **kwargs):
            with open(checkresultfile, 'a') as res_file:
                res_file.write('=begin=' + '\n')

            check_func(*args, **kwargs)

            with open(checkresultfile, 'a') as res_file:
                res_file.write('=end=' + '\n')
            return check_func

        return addingReminder

    return process_reminder_decorator


@log_detection_res(detect_items='srlg conflict detection')
def relay_srlg_conflict_detect():
    with open(checkresultfile, 'a') as output_file:
        output_file.write('ctx' + "\n")


relay_srlg_conflict_detect()