diff --git a/.travis.yml b/.travis.yml
index ed1d8b9..ea494de 100644
--- a/.travis.yml
+++ b/.travis.yml
@@ -1,5 +1,5 @@
 language: python
-dist: trusty
+dist: bionic
 
 script:
     - python setup.py test
@@ -18,7 +18,8 @@ branches:
 
 python:
   - "2.7"
-  - "3.3"
-  - "3.4"
   - "3.5"
-  - "3.6-dev"
+  - "3.6"
+  - "3.7"
+  - "3.8"
+  - "3.9"
diff --git a/binpacking/utilities.py b/binpacking/utilities.py
index 1b16ff2..22b8a34 100644
--- a/binpacking/utilities.py
+++ b/binpacking/utilities.py
@@ -8,34 +8,34 @@
 
 def load_csv(filepath,weight_column,has_header=False,delim=',',quotechar='"'):
 
+    weight_col_is_str = isinstance(weight_column,basestring)
+
+    if weight_col_is_str and not has_header:
+        raise Exception("weight key "+weight_column+" useless, since given csv has no header")
+
     with open(filepath) as csvfile:
         reader = csv.reader(csvfile, delimiter=delim, quotechar=quotechar)
 
         data = []
         row_count = 0
         header = None
-        
+
         for row in reader:
 
-            if row_count>0:
-                row[weight_column] = float(row[weight_column])
-                data.append(row)
-            elif has_header:
+            if has_header and row_count == 0:
                 header = row
-                if isinstance(weight_column,basestring):
-                    if has_header:
-                        if weight_column in header:
-                            weight_column = header.index(weight_column)
-                        else:
-                            raise Exception("weight key "+weight_column+" not found in header")
+                if weight_column in header:
+                    weight_column = header.index(weight_column)
+                else:
+                    raise Exception("weight key "+weight_column+" not found in header")
             else:
-                if isinstance(weight_column,basestring):
-                    raise Exception("weight key "+weight_column+" useless, since given csv has no header")
+                row[weight_column] = float(row[weight_column])
+                data.append(row)
 
             row_count += 1
 
 
-    return data,weight_column,header
+    return data, weight_column, header
 
 
 def print_binsizes(bins,weight_column):
@@ -43,7 +43,6 @@ def print_binsizes(bins,weight_column):
     formatstr = "%0" + str(len(str(len(bins)-1))) + "d"
     for ib,b in enumerate(bins):
         print(formatstr % ib, sum([t[weight_column] for t in b]))
-    
 
 def save_csvs(bins,filepath,header,delim=',',quotechar='"'):
     filename, file_extension = os.path.splitext(filepath)
@@ -52,7 +51,7 @@ def save_csvs(bins,filepath,header,delim=',',quotechar='"'):
 
     for ib,b in enumerate(bins):
         current_path = filename + "_" + formatstr % ib + file_extension
-        with open(current_path,"w") as csvfile:            
+        with open(current_path,"w") as csvfile:
             writer = csv.writer(csvfile, delimiter=delim, quotechar=quotechar, quoting=csv.QUOTE_MINIMAL)
             if header is not None:
                 writer.writerow(header)
diff --git a/examples/hamlet_word_count_00.csv b/examples/hamlet_word_count_00.csv
index d4b4112..3796dfc 100644
--- a/examples/hamlet_word_count_00.csv
+++ b/examples/hamlet_word_count_00.csv
@@ -1,97 +1,5 @@
-the,1206.0
-we,151.0
-from,107.0
-let,92.0
-would,78.0
-give,65.0
-an,59.0
-one,55.0
-ros,53.0
-horatio,43.0
-take,38.0
-polonius,35.0
-within,32.0
-nothing,30.0
-been,28.0
-away,26.0
-comes,24.0
-about,22.0
-done,21.0
-means,21.0
-keep,19.0
-form,18.0
-once,17.0
-is't,16.0
-thoughts,16.0
-etexts,15.0
-grief,14.0
-welcome,14.0
-duty,13.0
-grace,13.0
-awhile,12.0
-thousand,12.0
-neither,11.0
-through,11.0
-villain,11.0
-full,11.0
-passion,11.0
-let's,10.0
-arms,9.0
-behind,9.0
-falls,9.0
-aside,9.0
-shows,9.0
-understand,8.0
-says,8.0
-wrong,8.0
-hope,8.0
-return,8.0
-brother's,7.0
-beseech,7.0
-shot,7.0
-loves,7.0
-fool,7.0
-sorrow,6.0
-cornelius,6.0
-ambition,6.0
-double,6.0
-cold,6.0
-gifts,6.0
-danish,6.0
-ii,6.0
-struck,6.0
-stir,5.0
-statement,5.0
-souls,5.0
-among,5.0
-man's,5.0
-present,5.0
-liberty,5.0
-blessing,5.0
-marriage,5.0
-flesh,5.0
-burial,5.0
-prologue,5.0
-safety,5.0
-flourish,5.0
-servant,5.0
-request,4.0
-breathe,4.0
-favour,4.0
-forget,4.0
-reach,4.0
-hecuba,4.0
-hence,4.0
-twice,4.0
-legal,4.0
-rose,4.0
-b',4.0
-didst,4.0
-past,4.0
-possible,4.0
-certain,4.0
-william,4.0
-lives,4.0
-hundred,4.0
-hall,4.0
-ye,4.0
+word,count
+to,797.0
+of,732.0
+in,444.0
+pray,27.0
diff --git a/examples/hamlet_word_count_01.csv b/examples/hamlet_word_count_01.csv
index f744620..b0671ad 100644
--- a/examples/hamlet_word_count_01.csv
+++ b/examples/hamlet_word_count_01.csv
@@ -1,98 +1,5 @@
-and,1005.0
-he,212.0
-are,141.0
-o,104.0
-at,97.0
-there,74.0
-enter,66.0
-should,59.0
-am,55.0
-man,51.0
-had,44.0
-own,39.0
-guil,35.0
-mine,32.0
-again,30.0
-pray,27.0
-any,26.0
-nay,25.0
-call,22.0
-players,21.0
-son,21.0
-hand,19.0
-thing,18.0
-ear,17.0
-question,16.0
-majesty,16.0
-between,15.0
-o'er,14.0
-another,14.0
-spirit,13.0
-gentleman,13.0
-hands,12.0
-second,12.0
-men,11.0
-name,11.0
-takes,11.0
-fire,11.0
-fine,10.0
-peace,10.0
-doubt,10.0
-fall,9.0
-strange,9.0
-note,9.0
-offence,9.0
-back,8.0
-wife,8.0
-to't,8.0
-shame,8.0
-sit,8.0
-public,7.0
-already,7.0
-woman,7.0
-next,7.0
-husband,7.0
-reynaldo,6.0
-information,6.0
-re-enter,6.0
-feed,6.0
-wouldst,6.0
-dare,6.0
-beauty,6.0
-prince,6.0
-confess,6.0
-house,5.0
-sudden,5.0
-slain,5.0
-withal,5.0
-'gainst,5.0
-perhaps,5.0
-property,5.0
-author,5.0
-cry,5.0
-mass,5.0
-player,5.0
-damages,5.0
-university,5.0
-received,5.0
-drown'd,5.0
-expense,4.0
-remembrance,4.0
-poison'd,4.0
-armed,4.0
-spade,4.0
-turn'd,4.0
-wild,4.0
-habit,4.0
-begun,4.0
-fort,4.0
-honour'd,4.0
-length,4.0
-four,4.0
-so',4.0
-forgot,4.0
-wi',4.0
-sorry,4.0
-flowers,4.0
-lights,4.0
-unnatural,4.0
+word,count
+you,592.0
+a,563.0
+i,541.0
+his,297.0
diff --git a/examples/hamlet_word_count_02.csv b/examples/hamlet_word_count_02.csv
index 4417ff6..72e2485 100644
--- a/examples/hamlet_word_count_02.csv
+++ b/examples/hamlet_word_count_02.csv
@@ -1,99 +1,7 @@
-to,797.0
-for,269.0
-so,197.0
-if,131.0
-hamlet,102.0
-pol,86.0
-well,71.0
-very,65.0
-i'll,56.0
-say,53.0
-see,48.0
-can,39.0
-nor,38.0
-etext,34.0
-night,31.0
-both,29.0
-sweet,26.0
-great,26.0
-set,24.0
-i',22.0
-ber,21.0
-words,20.0
-use,20.0
-little,18.0
-please,17.0
-youth,16.0
-last,16.0
-live,15.0
-mark,14.0
-work,14.0
-kind,13.0
-we'll,13.0
-help,12.0
-drink,12.0
-revenge,11.0
-he's,11.0
-bed,11.0
-fortune,11.0
-deed,10.0
-aught,10.0
-phrase,10.0
-swear,9.0
-walk,9.0
-bernardo,9.0
-letters,9.0
-fran,8.0
-list,8.0
-power,8.0
-law,8.0
-looks,8.0
-needs,7.0
-rank,7.0
-dies,7.0
-service,7.0
-water,6.0
-fault,6.0
-others,6.0
-shape,6.0
-choose,6.0
-health,6.0
-copy,6.0
-buried,6.0
-hot,6.0
-bad,6.0
-heavy,6.0
-sing,5.0
-knew,5.0
-france,5.0
-ten,5.0
-slave,5.0
-patience,5.0
-bodies,5.0
-spirits,5.0
-fortune's,5.0
-million,5.0
-wit,5.0
-beard,5.0
-terms,5.0
-brains,5.0
-freely,4.0
-pate,4.0
-tale,4.0
-pleasure,4.0
-mock,4.0
-fast,4.0
-cries,4.0
-wear,4.0
-motion,4.0
-stars,4.0
-stronger,4.0
-modesty,4.0
-fingers,4.0
-sigh,4.0
-thrice,4.0
-thence,4.0
-reads,4.0
-months,4.0
-directly,4.0
-ass,4.0
+word,count
+my,513.0
+it,428.0
+that,391.0
+is,359.0
+with,274.0
+ay,35.0
diff --git a/examples/hamlet_word_count_03.csv b/examples/hamlet_word_count_03.csv
index b11d123..073c2ae 100644
--- a/examples/hamlet_word_count_03.csv
+++ b/examples/hamlet_word_count_03.csv
@@ -1,100 +1,8 @@
-of,732.0
-with,274.0
+word,count
+ham,358.0
+this,332.0
+not,319.0
+for,269.0
+but,263.0
+your,252.0
 what,201.0
-no,148.0
-hor,111.0
-her,91.0
-know,75.0
-love,66.0
-why,60.0
-upon,55.0
-father,51.0
-who,44.0
-exit,39.0
-mar,35.0
-dead,32.0
-indeed,30.0
-even,27.0
-head,26.0
-earth,24.0
-those,23.0
-till,21.0
-poor,20.0
-england,20.0
-father's,18.0
-long,17.0
-that's,16.0
-hast,16.0
-rest,15.0
-answer,14.0
-word,14.0
-dost,13.0
-daughter,13.0
-gentlemen,12.0
-right,12.0
-mind,11.0
-thought,11.0
-remember,11.0
-best,11.0
-hamlet's,10.0
-near,10.0
-hell,10.0
-brother,9.0
-less,9.0
-small,9.0
-came,9.0
-soft,8.0
-sun,8.0
-on't,8.0
-break,8.0
-joy,8.0
-coming,7.0
-top,7.0
-wholesome,7.0
-capt,7.0
-laugh,6.0
-stood,6.0
-bid,6.0
-cast,6.0
-whilst,6.0
-wager,6.0
-sister,6.0
-damned,6.0
-brought,6.0
-new,6.0
-toward,6.0
-themselves,5.0
-vows,5.0
-fly,5.0
-christian,5.0
-damn'd,5.0
-hearing,5.0
-went,5.0
-trumpet,5.0
-told,5.0
-in's,5.0
-visage,5.0
-adieu,5.0
-twelve,5.0
-cannon,5.0
-otherwise,4.0
-whereto,4.0
-main,4.0
-bosom,4.0
-calls,4.0
-desires,4.0
-lead,4.0
-shortly,4.0
-white,4.0
-yea,4.0
-return'd,4.0
-consent,4.0
-want,4.0
-anything,4.0
-hang,4.0
-special,4.0
-bestow,4.0
-editions,4.0
-angel,4.0
-if't,3.0
-idle,3.0
diff --git a/examples/hamlet_word_count_04.csv b/examples/hamlet_word_count_04.csv
index ea53a35..3779f04 100644
--- a/examples/hamlet_word_count_04.csv
+++ b/examples/hamlet_word_count_04.csv
@@ -1,101 +1,11 @@
-you,592.0
-his,297.0
+word,count
+be,229.0
+me,229.0
+as,224.0
 lord,221.0
-or,154.0
-our,131.0
-more,101.0
-may,85.0
-them,72.0
-hath,64.0
-their,57.0
-where,53.0
-time,47.0
-laertes,43.0
-mother,37.0
-ghost,32.0
-whose,31.0
-leave,28.0
-matter,27.0
-world,26.0
-scene,24.0
-before,22.0
-fair,21.0
-fear,20.0
-off,20.0
-blood,18.0
-faith,17.0
-speech,16.0
-therefore,16.0
-things,15.0
-ever,14.0
-gone,14.0
-thine,13.0
-after,13.0
-together,12.0
-saw,12.0
-to-night,11.0
-given,11.0
-business,11.0
-face,11.0
-particular,10.0
-seem,10.0
-lie,10.0
-almost,9.0
-sight,9.0
-action,9.0
-age,9.0
-known,8.0
-osric,8.0
-devil,8.0
-forth,8.0
-wilt,8.0
-print,7.0
-turn,7.0
-desire,7.0
-beg,7.0
-medium,6.0
-laid,6.0
-common,6.0
-files,6.0
-proof,6.0
-rather,6.0
-false,6.0
-lies,6.0
-seal'd,6.0
-home,6.0
-piece,6.0
-holds,5.0
-works,5.0
-morning,5.0
-short,5.0
-star,5.0
-report,5.0
-conceit,5.0
-image,5.0
-shalt,5.0
-distribute,5.0
-dread,5.0
-soldiers,5.0
-gracious,5.0
-complete,4.0
-bones,4.0
-commend,4.0
-chamber,4.0
-paid,4.0
-express,4.0
-lov'd,4.0
-ladies,4.0
-sick,4.0
-wittenberg,4.0
-wide,4.0
-meant,4.0
-pause,4.0
-brief,4.0
-release,4.0
-following,4.0
-kept,4.0
-quality,4.0
-cousin,4.0
-priam,4.0
-good-night,4.0
-bitter,3.0
+he,212.0
+so,197.0
+him,195.0
+king,193.0
+have,185.0
+shall,114.0
diff --git a/examples/hamlet_word_count_05.csv b/examples/hamlet_word_count_05.csv
index 4eb383e..c3be5a6 100644
--- a/examples/hamlet_word_count_05.csv
+++ b/examples/hamlet_word_count_05.csv
@@ -1,101 +1,16 @@
-a,563.0
-not,319.0
-as,224.0
+word,count
+will,174.0
 do,156.0
+or,154.0
+we,151.0
+no,148.0
+are,141.0
+by,140.0
 on,140.0
-now,98.0
-was,83.0
-go,70.0
-must,62.0
-oph,58.0
-than,54.0
-clown,47.0
-heaven,43.0
-exeunt,36.0
-project,33.0
-might,31.0
-dear,28.0
-down,27.0
-never,26.0
-true,23.0
-day,23.0
-mad,21.0
-since,20.0
-friends,19.0
-act,19.0
-else,17.0
-there's,16.0
-watch,15.0
-fortinbras,15.0
-tongue,15.0
-none,13.0
-gertrude,13.0
-haste,13.0
-ho,12.0
-voice,12.0
-fit,12.0
-alas,11.0
-receive,11.0
-far,11.0
-hour,10.0
-skull,10.0
-honour,10.0
-judgment,9.0
-courtier,9.0
-breath,9.0
-noise,8.0
-hither,8.0
-elsinore,8.0
-lost,8.0
-read,8.0
-truly,8.0
-light,8.0
-gives,7.0
-voltimand,7.0
-year,7.0
-mother's,6.0
-guilty,6.0
-circumstance,6.0
-visit,6.0
-whom,6.0
-court,6.0
-truth,6.0
-crown,6.0
-choice,6.0
-kill'd,6.0
-fare,6.0
-whereon,5.0
-commission,5.0
-honesty,5.0
-teach,5.0
-treason,5.0
-longer,5.0
-eat,5.0
-writ,5.0
-motive,5.0
-prison,5.0
-dream,5.0
-mercy,5.0
-th',5.0
-throat,4.0
-prepared,4.0
-deep,4.0
-often,4.0
-treasure,4.0
-remove,4.0
-thrift,4.0
-few,4.0
-cursed,4.0
-incestuous,4.0
-quantity,4.0
-ftp,4.0
-frame,4.0
-leisure,4.0
-fain,4.0
-date,4.0
-addition,4.0
-years,4.0
-puts,4.0
-liability,4.0
-thinking,4.0
-feeling,3.0
+if,131.0
+our,131.0
+all,125.0
+queen,117.0
+hor,111.0
+from,107.0
+there,74.0
diff --git a/examples/hamlet_word_count_06.csv b/examples/hamlet_word_count_06.csv
index d57dfc4..79b1ddf 100644
--- a/examples/hamlet_word_count_06.csv
+++ b/examples/hamlet_word_count_06.csv
@@ -1,101 +1,24 @@
-i,541.0
-this,332.0
-me,229.0
-will,174.0
-queen,117.0
+word,count
+o,104.0
+thou,103.0
 they,102.0
+hamlet,102.0
+more,101.0
+come,99.0
+good,99.0
+now,98.0
+at,97.0
+let,92.0
+her,91.0
+how,89.0
 thy,86.0
-sir,72.0
-laer,62.0
-when,57.0
-out,55.0
-think,47.0
-tell,43.0
-ay,35.0
-soul,34.0
-cannot,30.0
-guildenstern,29.0
-heart,27.0
-hold,26.0
-against,23.0
-seen,22.0
-denmark,22.0
-old,20.0
-gutenberg,19.0
-many,18.0
-art,17.0
-noble,17.0
-castle,15.0
-said,15.0
-sings,14.0
-lady,14.0
-rey,13.0
-norway,13.0
-murder,12.0
-air,12.0
-being,12.0
-sure,11.0
-foul,11.0
-way,11.0
-memory,10.0
-p,10.0
-while,10.0
-every,9.0
-thank,9.0
-person,9.0
-three,8.0
-grow,8.0
-fashion,8.0
-attendants,8.0
-unto,8.0
-conscience,8.0
-obey,7.0
-point,7.0
-seems,7.0
-bloody,7.0
-lose,7.0
-over,6.0
-vile,6.0
-below,6.0
-lack,6.0
-fat,6.0
-move,6.0
-wish,6.0
-domain,6.0
-desperate,6.0
-wicked,6.0
-mortal,5.0
-yes,5.0
-countenance,5.0
-arm,5.0
-table,5.0
-kingdom,5.0
-land,5.0
-beneath,5.0
-nunnery,5.0
-perchance,5.0
-base,5.0
-woul't,5.0
-bound,5.0
-native,4.0
-methought,4.0
-file,4.0
-lands,4.0
-violence,4.0
-tender,4.0
-glad,4.0
-sort,4.0
-polack,4.0
-affair,4.0
-tend,4.0
-defect,4.0
-grows,4.0
-draws,4.0
-pity,4.0
-argument,4.0
-ready,4.0
-warrant,4.0
-iv,4.0
-cost,4.0
-prepare,4.0
-borne,3.0
+pol,86.0
+may,85.0
+most,85.0
+was,83.0
+like,80.0
+would,78.0
+know,75.0
+us,73.0
+them,72.0
+words,20.0
diff --git a/examples/hamlet_word_count_07.csv b/examples/hamlet_word_count_07.csv
index e68b790..d3ef96a 100644
--- a/examples/hamlet_word_count_07.csv
+++ b/examples/hamlet_word_count_07.csv
@@ -1,101 +1,34 @@
-my,513.0
-ham,358.0
-be,229.0
-have,185.0
-shall,114.0
-come,99.0
-most,85.0
+word,count
+sir,72.0
+'tis,71.0
+well,71.0
+go,70.0
 which,66.0
+love,66.0
+enter,66.0
+give,65.0
 did,65.0
+then,65.0
+very,65.0
+hath,64.0
+must,62.0
+laer,62.0
+speak,60.0
+why,60.0
+an,59.0
+should,59.0
+such,58.0
 thee,58.0
+oph,58.0
+when,57.0
+their,57.0
+some,56.0
+i'll,56.0
+one,55.0
+am,55.0
+upon,55.0
+make,55.0
+out,55.0
 here,54.0
+than,54.0
 too,49.0
-thus,39.0
-look,38.0
-life,33.0
-hear,32.0
-were,28.0
-nature,27.0
-rosencrantz,26.0
-show,23.0
-eyes,22.0
-first,21.0
-himself,21.0
-end,19.0
-makes,18.0
-body,17.0
-young,17.0
-state,15.0
-eye,15.0
-something,14.0
-reason,14.0
-further,13.0
-what's,13.0
-grave,12.0
-sleep,12.0
-e'en,12.0
-myself,11.0
-wind,11.0
-only,11.0
-madam,10.0
-mean,10.0
-late,9.0
-seek,9.0
-days,9.0
-month,9.0
-lay,9.0
-here's,8.0
-gave,8.0
-times,8.0
-pale,8.0
-lordship,8.0
-either,7.0
-wherein,7.0
-whether,7.0
-tears,7.0
-effect,7.0
-foils,6.0
-audience,6.0
-beast,6.0
-dumb,6.0
-maid,6.0
-send,6.0
-mouth,6.0
-need,6.0
-poison,6.0
-dull,6.0
-ah,5.0
-save,5.0
-plain,5.0
-fee,5.0
-ambassadors,5.0
-drown,5.0
-carriages,5.0
-books,5.0
-&c,5.0
-natural,5.0
-silence,5.0
-'twas,5.0
-humbly,5.0
-iii,4.0
-lend,4.0
-discretion,4.0
-assume,4.0
-affection,4.0
-secret,4.0
-imports,4.0
-six,4.0
-snow,4.0
-clouds,4.0
-horrible,4.0
-also,4.0
-sits,4.0
-weeds,4.0
-country,4.0
-priest,4.0
-censure,4.0
-danes,4.0
-grown,4.0
-change,4.0
-start,4.0
-gaming,3.0
diff --git a/examples/hamlet_word_count_08.csv b/examples/hamlet_word_count_08.csv
index c391ef5..322d1ee 100644
--- a/examples/hamlet_word_count_08.csv
+++ b/examples/hamlet_word_count_08.csv
@@ -1,101 +1,52 @@
-in,444.0
-is,359.0
-but,263.0
-him,195.0
-by,140.0
-good,99.0
-like,80.0
-us,73.0
-speak,60.0
-such,58.0
-make,55.0
+word,count
+these,54.0
+say,53.0
+where,53.0
+ros,53.0
+man,51.0
+father,51.0
 much,48.0
+see,48.0
+time,47.0
+clown,47.0
+think,47.0
+she,47.0
+had,44.0
+who,44.0
+horatio,43.0
+laertes,43.0
+heaven,43.0
+tell,43.0
 play,42.0
+yet,41.0
+can,39.0
+thus,39.0
+own,39.0
+exit,39.0
+take,38.0
+nor,38.0
+look,38.0
+up,37.0
 death,37.0
+mother,37.0
+exeunt,36.0
+polonius,35.0
+guil,35.0
+mar,35.0
+etext,34.0
+soul,34.0
+life,33.0
+could,33.0
+project,33.0
 into,32.0
+ghost,32.0
+within,32.0
+mine,32.0
+dead,32.0
+hear,32.0
 made,32.0
-god,28.0
-doth,27.0
-osr,25.0
-put,24.0
-without,22.0
-two,21.0
-madness,21.0
-believe,19.0
-has,18.0
-farewell,17.0
-better,17.0
-stand,15.0
-bear,15.0
-free,14.0
-yourself,14.0
-goes,13.0
-virtue,13.0
-ourselves,12.0
-ere,12.0
-bring,12.0
-o',11.0
-purpose,11.0
-honest,11.0
-excellent,10.0
-command,10.0
-draw,9.0
-ears,9.0
-uncle,9.0
-place,9.0
-custom,9.0
-black,8.0
-charge,8.0
-meet,8.0
-try,8.0
-heavens,8.0
-sound,7.0
-under,7.0
-enough,7.0
-do't,7.0
-ha,7.0
-ill,6.0
-cock,6.0
-brain,6.0
-hit,6.0
-pardon,6.0
-sea,6.0
-season,6.0
-touch,6.0
-herself,6.0
-danger,5.0
-hard,5.0
-unless,5.0
-shakespeare,5.0
-thyself,5.0
-moon,5.0
-gutenberg-tm,5.0
-arras,5.0
-door,5.0
-gentle,5.0
-keeps,5.0
-course,5.0
-warlike,5.0
-including,5.0
-half,5.0
-instant,4.0
-entertainment,4.0
-took,4.0
-follows,4.0
-cup,4.0
-sailors,4.0
-practice,4.0
-refund,4.0
-stands,4.0
-weep,4.0
-kill,4.0
-infinite,4.0
-states,4.0
-to-morrow,4.0
-brow,4.0
-seeing,4.0
-warranties,4.0
-bore,4.0
-sending,4.0
-drift,4.0
-golden,3.0
+other,32.0
+night,31.0
+whose,31.0
+might,31.0
+poor,20.0
diff --git a/examples/hamlet_word_count_09.csv b/examples/hamlet_word_count_09.csv
index 1b93418..0d084a6 100644
--- a/examples/hamlet_word_count_09.csv
+++ b/examples/hamlet_word_count_09.csv
@@ -1,101 +1,87 @@
-it,428.0
-that,391.0
-your,252.0
-king,193.0
-all,125.0
-thou,103.0
-how,89.0
-'tis,71.0
-then,65.0
-some,56.0
-these,54.0
-she,47.0
-yet,41.0
-up,37.0
-could,33.0
-other,32.0
+word,count
+cannot,30.0
+nothing,30.0
+again,30.0
+indeed,30.0
+guildenstern,29.0
+both,29.0
+leave,28.0
+dear,28.0
+were,28.0
+god,28.0
 ophelia,28.0
+been,28.0
+even,27.0
+matter,27.0
+down,27.0
+heart,27.0
+nature,27.0
+doth,27.0
 does,26.0
+sweet,26.0
+any,26.0
+head,26.0
 part,26.0
+away,26.0
+great,26.0
+world,26.0
+never,26.0
+hold,26.0
+rosencrantz,26.0
+osr,25.0
+nay,25.0
+earth,24.0
+put,24.0
 itself,24.0
+comes,24.0
+set,24.0
+scene,24.0
+true,23.0
+against,23.0
+show,23.0
+those,23.0
+day,23.0
+seen,22.0
+eyes,22.0
+without,22.0
 though,22.0
+about,22.0
+call,22.0
+i',22.0
+before,22.0
+denmark,22.0
+first,21.0
+two,21.0
 get,21.0
+done,21.0
+players,21.0
+ber,21.0
+till,21.0
+fair,21.0
+mad,21.0
+himself,21.0
+madness,21.0
 still,21.0
+means,21.0
+son,21.0
+fear,20.0
+since,20.0
+old,20.0
+use,20.0
+england,20.0
+off,20.0
+friends,19.0
+gutenberg,19.0
+end,19.0
+believe,19.0
 follow,19.0
+keep,19.0
+hand,19.0
+act,19.0
+many,18.0
+makes,18.0
+has,18.0
 cause,18.0
-find,17.0
-sword,16.0
-marry,16.0
-room,15.0
-each,14.0
-heard,14.0
-sent,13.0
-sense,13.0
-same,12.0
-oft,12.0
-marcellus,12.0
-'twere,11.0
-in't,11.0
-friend,11.0
-news,10.0
-thanks,10.0
-stay,9.0
-fell,9.0
-copyright,9.0
-alone,9.0
-ground,9.0
-fellow,8.0
-quick,8.0
-music,8.0
-king's,8.0
-woe,8.0
-money,7.0
-general,7.0
-dust,7.0
-whole,7.0
-march,7.0
-discourse,6.0
-pyrrhus,6.0
-speaks,6.0
-dane,6.0
-round,6.0
-pass,6.0
-wisdom,6.0
-yours,6.0
-anon,6.0
-knave,5.0
-disposition,5.0
-pay,5.0
-french,5.0
-dangerous,5.0
-figure,5.0
-hide,5.0
-quiet,5.0
-found,5.0
-colour,5.0
-fie,5.0
-above,5.0
-alexander,5.0
-throw,5.0
-begin,5.0
-presently,4.0
-direct,4.0
-die,4.0
-imagination,4.0
-got,4.0
-ecstasy,4.0
-impart,4.0
-commandment,4.0
-platform,4.0
-violent,4.0
-straight,4.0
-lest,4.0
-cunning,4.0
-ease,4.0
-wits,4.0
-lords,4.0
-methinks,4.0
-herein,4.0
-trumpets,4.0
-strong,4.0
-dozen,3.0
+form,18.0
+thing,18.0
+little,18.0
diff --git a/examples/hamlet_word_count_10.csv b/examples/hamlet_word_count_10.csv
new file mode 100644
index 0000000..b0d31d2
--- /dev/null
+++ b/examples/hamlet_word_count_10.csv
@@ -0,0 +1,144 @@
+word,count
+father's,18.0
+blood,18.0
+art,17.0
+body,17.0
+farewell,17.0
+find,17.0
+once,17.0
+ear,17.0
+please,17.0
+long,17.0
+faith,17.0
+else,17.0
+noble,17.0
+young,17.0
+better,17.0
+sword,16.0
+is't,16.0
+question,16.0
+youth,16.0
+that's,16.0
+speech,16.0
+there's,16.0
+marry,16.0
+thoughts,16.0
+majesty,16.0
+last,16.0
+hast,16.0
+therefore,16.0
+watch,15.0
+castle,15.0
+state,15.0
+stand,15.0
+fortinbras,15.0
+said,15.0
+eye,15.0
+bear,15.0
+room,15.0
+etexts,15.0
+between,15.0
+live,15.0
+rest,15.0
+things,15.0
+tongue,15.0
+sings,14.0
+something,14.0
+free,14.0
+each,14.0
+grief,14.0
+o'er,14.0
+mark,14.0
+answer,14.0
+ever,14.0
+lady,14.0
+reason,14.0
+yourself,14.0
+heard,14.0
+welcome,14.0
+another,14.0
+work,14.0
+word,14.0
+gone,14.0
+none,13.0
+gertrude,13.0
+rey,13.0
+further,13.0
+goes,13.0
+sent,13.0
+duty,13.0
+spirit,13.0
+kind,13.0
+dost,13.0
+thine,13.0
+haste,13.0
+norway,13.0
+what's,13.0
+virtue,13.0
+sense,13.0
+grace,13.0
+gentleman,13.0
+we'll,13.0
+daughter,13.0
+after,13.0
+ho,12.0
+murder,12.0
+grave,12.0
+ourselves,12.0
+same,12.0
+awhile,12.0
+hands,12.0
+help,12.0
+gentlemen,12.0
+together,12.0
+voice,12.0
+air,12.0
+sleep,12.0
+ere,12.0
+oft,12.0
+thousand,12.0
+second,12.0
+drink,12.0
+right,12.0
+saw,12.0
+fit,12.0
+being,12.0
+e'en,12.0
+bring,12.0
+marcellus,12.0
+neither,11.0
+men,11.0
+revenge,11.0
+mind,11.0
+to-night,11.0
+through,11.0
+name,11.0
+he's,11.0
+thought,11.0
+given,11.0
+alas,11.0
+sure,11.0
+myself,11.0
+o',11.0
+'twere,11.0
+villain,11.0
+takes,11.0
+bed,11.0
+remember,11.0
+business,11.0
+receive,11.0
+foul,11.0
+wind,11.0
+purpose,11.0
+in't,11.0
+full,11.0
+fire,11.0
+fortune,11.0
+best,11.0
+face,11.0
+far,11.0
+way,11.0
+only,11.0
+honest,11.0
+friend,11.0
+passion,11.0
diff --git a/examples/header.csv b/examples/header.csv
new file mode 100644
index 0000000..c9e1a71
--- /dev/null
+++ b/examples/header.csv
@@ -0,0 +1,5 @@
+word,freq
+foo,23
+bar,10
+eff,1
+you,8
diff --git a/examples/header_0.csv b/examples/header_0.csv
new file mode 100644
index 0000000..5bc796f
--- /dev/null
+++ b/examples/header_0.csv
@@ -0,0 +1,2 @@
+word,freq
+foo,23.0
diff --git a/examples/header_1.csv b/examples/header_1.csv
new file mode 100644
index 0000000..919b340
--- /dev/null
+++ b/examples/header_1.csv
@@ -0,0 +1,2 @@
+word,freq
+bar,10.0
diff --git a/examples/header_2.csv b/examples/header_2.csv
new file mode 100644
index 0000000..f4de20a
--- /dev/null
+++ b/examples/header_2.csv
@@ -0,0 +1,3 @@
+word,freq
+you,8.0
+eff,1.0
diff --git a/examples/headerless.csv b/examples/headerless.csv
new file mode 100644
index 0000000..70838b3
--- /dev/null
+++ b/examples/headerless.csv
@@ -0,0 +1,4 @@
+foo,23
+bar,10
+eff,1
+you,8
diff --git a/examples/headerless_0.csv b/examples/headerless_0.csv
new file mode 100644
index 0000000..91be5e0
--- /dev/null
+++ b/examples/headerless_0.csv
@@ -0,0 +1 @@
+foo,23.0
diff --git a/examples/headerless_1.csv b/examples/headerless_1.csv
new file mode 100644
index 0000000..61ad3af
--- /dev/null
+++ b/examples/headerless_1.csv
@@ -0,0 +1 @@
+bar,10.0
diff --git a/examples/headerless_2.csv b/examples/headerless_2.csv
new file mode 100644
index 0000000..902d171
--- /dev/null
+++ b/examples/headerless_2.csv
@@ -0,0 +1,2 @@
+you,8.0
+eff,1.0
diff --git a/setup.py b/setup.py
index a95c8a5..faaed9b 100644
--- a/setup.py
+++ b/setup.py
@@ -1,7 +1,7 @@
 from setuptools import setup
 
 setup(name='binpacking',
-      version='1.4.3',
+      version='1.4.5',
       description='Heuristic distribution of weighted items to bins (either a fixed number of bins or a fixed number of volume per bin). Data may be in form of list, dictionary, list of tuples or csv-file.',
       url='https://www.github.com/benmaier/binpacking',
       author='Benjamin F. Maier',
@@ -22,10 +22,10 @@
             },
       classifiers=['License :: OSI Approved :: MIT License',
                    'Programming Language :: Python :: 2.7',
-                   'Programming Language :: Python :: 3.3',
-                   'Programming Language :: Python :: 3.4',
                    'Programming Language :: Python :: 3.5',
                    'Programming Language :: Python :: 3.6',
                    'Programming Language :: Python :: 3.7'
+                   'Programming Language :: Python :: 3.8',
+                   'Programming Language :: Python :: 3.9'
                    ],
       zip_safe=False)