Skipping Error in For-Loop

Skipping error in for-loop

One (dirty) way to do it is to use tryCatch with an empty function for error handling. For example, the following code raises an error and breaks the loop :

for (i in 1:10) {
    print(i)
    if (i==7) stop("Urgh, the iphone is in the blender !")
}

[1] 1
[1] 2
[1] 3
[1] 4
[1] 5
[1] 6
[1] 7
Erreur : Urgh, the iphone is in the blender !

But you can wrap your instructions into a tryCatch with an error handling function that does nothing, for example :

for (i in 1:10) {
  tryCatch({
    print(i)
    if (i==7) stop("Urgh, the iphone is in the blender !")
  }, error=function(e){})
}

[1] 1
[1] 2
[1] 3
[1] 4
[1] 5
[1] 6
[1] 7
[1] 8
[1] 9
[1] 10

But I think you should at least print the error message to know if something bad happened while letting your code continue to run :

for (i in 1:10) {
  tryCatch({
    print(i)
    if (i==7) stop("Urgh, the iphone is in the blender !")
  }, error=function(e){cat("ERROR :",conditionMessage(e), "\n")})
}

[1] 1
[1] 2
[1] 3
[1] 4
[1] 5
[1] 6
[1] 7
ERROR : Urgh, the iphone is in the blender ! 
[1] 8
[1] 9
[1] 10

EDIT : So to apply tryCatch in your case would be something like :

for (v in 2:180){
    tryCatch({
        mypath=file.path("C:", "file1", (paste("graph",names(mydata[columnname]), ".pdf", sep="-")))
        pdf(file=mypath)
        mytitle = paste("anything")
        myplotfunction(mydata[,columnnumber]) ## this function is defined previously in the program
        dev.off()
    }, error=function(e){cat("ERROR :",conditionMessage(e), "\n")})
}

Skipping error message while using tcl for loop for creating multiple components

Generally speaking, assuming that *createentity comps name=pshell.$i id=$i command is correct (whatever it is, I really don't know!), to skip error messages in case of failure you should use try. This will not skip the command however, this just allows you to handle it gracefully.

There's no need to incr i before continue.

for {set i 10} {$i < 20} {incr i} {
  try {
    *createentity comps name=pshell.$i id=$i
  } on error {} {
    continue
  }
  puts $i
}

How to skip an error and in a for loop in R

We can create a function and then use tryCatch or possibly to skip the errors.

First create function f1 to get links to pictures,

#function f1
f1 = function(x){
  picture <- x %>% read_html() %>% html_element(".CmhTt") %>% html_attr("src")
}

apt <- pic_flat$apt_link

#now loop by skipping errors
apt_pic = lapply(apt, possibly(f1, NA))

Ignoring an error message to continue with the loop in python

It is generally a bad practice to suppress errors or exceptions without handling them, but this can be easily done like this:

try:
    # block raising an exception
except:
    pass # doing nothing on exception

This can obviously be used in any other control statement, such as a loop:

for i in xrange(0,960):
    try:
        ... run your code
    except:
        pass

skip an error row in a for loop

You want something like:

for row in csv_file:
    try: 
        x = float(row['Close Ask']) - float(row['Close Bid'])
    except ValueError:
        continue
    else:
        # now keep going doing something with x
        ...

How to skip over errored lines in a for loop

Those try...except blocks, specially those for very specific errors such as KeyError should be added around only the lines where it matter.

If you want to be able to continue processing, at least put the block inside the for loop so on error it will skip to the next item on the iteration. But even better would be to verify when the values are actually necessary and just replace them with a dummy value in case they are not.

For example: for row in item['addresses']:

Could be: for row in item.get('addresses', []):

Therefore you will accept items without an address

---

Related Topics