How to Convert Comma-Separated String to List

How to convert comma-separated String to List?

Convert comma separated String to List

List<String> items = Arrays.asList(str.split("\\s*,\\s*"));

The above code splits the string on a delimiter defined as: zero or more whitespace, a literal comma, zero or more whitespace which will place the words into the list and collapse any whitespace between the words and commas.

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Please note that this returns simply a wrapper on an array: you CANNOT for example .remove() from the resulting List. For an actual ArrayList you must further use new ArrayList<String>.

How to convert comma-delimited string to list in Python?

You can use the str.split method.

>>> my_string = 'A,B,C,D,E'
>>> my_list = my_string.split(",")
>>> print my_list
['A', 'B', 'C', 'D', 'E']

If you want to convert it to a tuple, just

>>> print tuple(my_list)
('A', 'B', 'C', 'D', 'E')

If you are looking to append to a list, try this:

>>> my_list.append('F')
>>> print my_list
['A', 'B', 'C', 'D', 'E', 'F']

How to convert a comma separated String to ArrayList in Java

The ArrayList returned by Arrays.asList is not java.util.ArrayList. It's java.util.Arrays.ArrayList. So you can't cast it to java.util.ArrayList.

You need to pass the list to the constructor of java.util.ArrayList class:

List<String> items = new ArrayList<String>(Arrays.asList(CommaSeparated.split("\\s*,\\s*")));

or, you can simply assign the result:

List<String> items = Arrays.asList(CommaSeparated.split("\\s*,\\s*"));

but mind you, Arrays.asList returns a fixed size list. You cannot add or remove anything into it. If you want to add or remove something, you should use the 1st version.

P.S: You should use List as reference type instead of ArrayList.

How can I convert a comma delimited string to a list of integers?

Something like this

var results = yearsString.Split(',').Select(x => int.Parse(x.Trim()));

Note : There is no fault tolerance in this approach, if they cant be converted to int this will blow up with an exception

And just for fun here is a an approach using pointers unsafe and fixed

fixed (char* pInput = Input)
{
   var len = pInput + Input.Length;
   var current = 0;
   var results = new List<int>();

   for (var p = pInput; p < len; p++)
   {
      if (*p >= 48 & *p <= 58)
         current = current * 10 + *p - 48;          
      else if (*p == ',')
      {
         results.Add(current);
         current = 0;
      }
   }

   results.Add(current);
   return results;
}

Benchmarks

Just because i was bored

----------------------------------------------------------------------------
Mode             : Release (64Bit)
Test Framework   : .NET Framework 4.7.1 (CLR 4.0.30319.42000)
----------------------------------------------------------------------------
Operating System : Microsoft Windows 10 Pro
Version          : 10.0.17134
----------------------------------------------------------------------------
CPU Name         : Intel(R) Core(TM) i7-2600 CPU @ 3.40GHz
Description      : Intel64 Family 6 Model 42 Stepping 7
Cores (Threads)  : 4 (8)      : Architecture  : x64
Clock Speed      : 3401 MHz   : Bus Speed     : 100 MHz
L2Cache          : 1 MB       : L3Cache       : 8 MB
----------------------------------------------------------------------------

Test 1

--- Standard input --------------------------------------------------------
| Value  |    Average |    Fastest |    Cycles | Garbage | Test |    Gain |
--- Scale 100 ---------------------------------------------- Time 0.003 ---
| Unsafe |   2.304 µs |   2.101 µs |   9.298 K | 0.000 B | Pass | 90.28 % |
| Linq   |  23.711 µs |  22.214 µs |  82.700 K | 0.000 B | Base |  0.00 % |
--- Scale 1,000 -------------------------------------------- Time 0.046 ---
| Unsafe |  21.697 µs |  21.013 µs |  75.490 K | 0.000 B | Pass | 90.41 % |
| Linq   | 226.218 µs | 205.332 µs | 768.447 K | 0.000 B | Base |  0.00 % |
--- Scale 10,000 ------------------------------------------- Time 0.250 ---
| Unsafe | 214.526 µs | 200.829 µs | 733.557 K | 0.000 B | Pass | 89.93 % |
| Linq   |   2.130 ms |   1.996 ms |   7.257 M | 0.000 B | Base |  0.00 % |
--- Scale 100,000 ------------------------------------------ Time 2.906 ---
| Unsafe |   2.303 ms |   2.063 ms |   7.680 M | 0.000 B | Pass | 90.99 % |
| Linq   |  25.571 ms |  22.624 ms |  84.808 M | 0.000 B | Base |  0.00 % |
--- Scale 1,000,000 --------------------------------------- Time 36.594 ---
| Unsafe |  23.061 ms |  21.910 ms |  78.356 M | 0.000 B | Pass | 93.07 % |
| Linq   | 332.639 ms | 274.595 ms |   1.055 B | 0.000 B | Base |  0.00 % |
---------------------------------------------------------------------------

Convert comma delimited string to list

I'm pretty sure you just need to split the matched string by , using String.Split().

$Credentials = 'Credentials: myacct1,myacct2'

$runtimes = $Credentials -match "Credentials: (?<content>.*)"
$runtimeList = $matches['content'].Split(",")
Foreach ($runtime in $runtimeList)
{
    Write-Host $runtime
}

# Output:
# myacct1
# myacct2

How can I convert comma separated string into a List int

Here is one way of doing it:

List<int> TagIds = tags.Split(',').Select(int.Parse).ToList();

Convert comma separated string into list

Like this:

$string = "word1,word2,word3,word4";
$string = explode(",",$string);
foreach ($string as $str) {
    echo "<li>".$str."</li>";
}

You can explode() the string into an array, loop through it, and output the results into a list option.

Dataframe: Cell Level: Convert Comma Separated String to List

• Use pandas.Series.str.split to split the string into a list.

# use str split on the column
df.mgrs_grids = df.mgrs_grids.str.split(',')

# display(df)
   driver_code journey_code                                                                                                                                       mgrs_grids
0      7211863  7211863-140                            [18TWL927129, 18TWL888113, 18TWL888113, 18TWL887113, 18TWL888113, 18TWL887113, 18TWL887113, 18TWL887113, 18TWL903128]
1      7211863  7211863-105  [18TWL927129, 18TWL939112, 18TWL939112, 18TWL939113, 18TWL939113, 18TWL939113, 18TWL939113, 18TWL939113, 18TWL939113, 18TWL960111, 18TWL960112]
2      7211863   7211863-50                            [18TWL927129, 18TWL889085, 18TWL889085, 18TWL888085, 18TWL888085, 18TWL888085, 18TWL888085, 18TWL888085, 18TWL890085]
3      7211863  7211863-109               [18TWL927129, 18TWL952106, 18TWL952106, 18TWL952106, 18TWL952106, 18TWL952106, 18TWL952106, 18TWL952106, 18TWL952105, 18TWL951103]

print(type(df.loc[0, 'mgrs_grids']))
[out]:
list

separate row per value

• After creating a column of lists.
• Use pandas.DataFrame.explode to create separate rows for each value in the list.

# get a separate row for each value
df = df.explode('mgrs_grids').reset_index(drop=True)

# display(df.hea())
   driver_code journey_code   mgrs_grids
0      7211863  7211863-140  18TWL927129
1      7211863  7211863-140  18TWL888113
2      7211863  7211863-140  18TWL888113
3      7211863  7211863-140  18TWL887113
4      7211863  7211863-140  18TWL888113

Update

• Here is another option, which combines the 'journey_code' to the front of 'mgrs_grids', and then splits the string into a list.
  
  • This list is assigned back to 'mgrs_grids', but can also be assigned to a new column.

# add the journey code to mgrs_grids and then split
df.mgrs_grids = (df.journey_code + ',' + df.mgrs_grids).str.split(',')

# display(df.head())
   driver_code journey_code                                                                                                                                                    mgrs_grids
0      7211863  7211863-140                            [7211863-140, 18TWL927129, 18TWL888113, 18TWL888113, 18TWL887113, 18TWL888113, 18TWL887113, 18TWL887113, 18TWL887113, 18TWL903128]
1      7211863  7211863-105  [7211863-105, 18TWL927129, 18TWL939112, 18TWL939112, 18TWL939113, 18TWL939113, 18TWL939113, 18TWL939113, 18TWL939113, 18TWL939113, 18TWL960111, 18TWL960112]
2      7211863   7211863-50                             [7211863-50, 18TWL927129, 18TWL889085, 18TWL889085, 18TWL888085, 18TWL888085, 18TWL888085, 18TWL888085, 18TWL888085, 18TWL890085]
3      7211863  7211863-109               [7211863-109, 18TWL927129, 18TWL952106, 18TWL952106, 18TWL952106, 18TWL952106, 18TWL952106, 18TWL952106, 18TWL952106, 18TWL952105, 18TWL951103]

# output to nested list
df.mgrs_grids.tolist()

[out]:
[['7211863-140', '18TWL927129', '18TWL888113', '18TWL888113', '18TWL887113', '18TWL888113', '18TWL887113', '18TWL887113', '18TWL887113', '18TWL903128'],
 ['7211863-105', '18TWL927129', '18TWL939112', '18TWL939112', '18TWL939113', '18TWL939113', '18TWL939113', '18TWL939113', '18TWL939113', '18TWL939113', '18TWL960111', '18TWL960112'],
 ['7211863-50', '18TWL927129', '18TWL889085', '18TWL889085', '18TWL888085', '18TWL888085', '18TWL888085', '18TWL888085', '18TWL888085', '18TWL890085'],
 ['7211863-109', '18TWL927129', '18TWL952106', '18TWL952106', '18TWL952106', '18TWL952106', '18TWL952106', '18TWL952106', '18TWL952106', '18TWL952105', '18TWL951103']]

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