diff --git a/deva_iast_comp/data.txt b/deva_iast_comp/data.txt
new file mode 100644
index 0000000..c720817
--- /dev/null
+++ b/deva_iast_comp/data.txt
@@ -0,0 +1,461 @@
+a:abnormal
+aMSaprakalpanA:aṃśa-kalpanā
+aGnya:ághnya ({%also%} {@-yá@})
+adfpita:á-dṛp-ita {%or%} {@-ta
+adya:a-dyá (ā́) {%ad.%} to-day
+aDarozWa,°rOzWa:adhara‡oṣṭha
+aDaHsTa:adhaḥ-stha
+aDipuruza:adhi-pŭruṣa
+aDirukmamandiragavAkzam:abnormal
+aDIk:abnormal
+anirhARarca:a-nirhāṇa‡ṛca
+anUpa:anūpá [anu+ap-a]
+antaHsaMjYa:antaḥ-saṃ-jña
+anvavekzA:anu‡avekṣ-ā {%f.%} regard
+aparAvfttaBAgaDeya:abnormal
+apartu:apa‡ṛtu
+aprOQa:a-pra‡ūḍha
+arDarca:ardha‡ṛcá
+arvAkkAlikatA:arvāk‡kālika-tā
+arvAcIna:arvācī́na ({%or%} á)
+alomaka:a-lómaka ({%or%} áka)
+alohita:a-lóhita ({%or%} tá)
+avarti:áva‡ṛti
+aviBUzaRaparicCada:abnormal
+aSanAyA:aśanā́yā ({%or%} ā́)
+asaNga:á-saṅga ({%or%} á)
+asma:á-sma ({%or%} á)
+asmattas:asmat-tas (= {%ab.%} asmát)
+asyavAmIya:‘asya-vām’-īya
+ahar:áhar ({%used as the middle base of%} áhan)
+ahas:áhas = áhar: {@-kara
+A:abnormal
+Agama:ā́-gama {%a.%} coming up; {%m.%} arrival
+AN:abnormal
+AcArya:ā-cāryâ [{%fp.%} to be gone to]
+AtiraScIna:ā-tira{%s-k-%}īna
+AtmecCA:abnormal
+AtmOpamya:ātma‡aupamya
+Aruj:ā-ruj (-°)
+AruRa:āruṇ-a ({@ī@})
+Arta:ā’‡ṛta
+Arti:ā’‡ṛti
+Asana:ā́s-ana ({%or%} á)
+AsapiRqakriyAkarma:abnormal
+iq:íḍ {%f.%} comfort; oblation
+itara:í-tara ({%n.%} {@-d@}; {%V. also%} {@-m@})
+iti:í-ti {%or%} i-tí
+indrApUzan:índrā-pū́ṣan ({%or%} indrā-pūṣán)
+ihAmutraPalaBogavirAga:abnormal
+Ij:ĪJ I.Ā. ī́j{@a-te
+Idfkza:īdṛkṣa ({@ā@})
+ISAna:ī́ś-āna ({%or%} {@á@})
+ujjfmBa:uj-ṛmbha
+ujJ:UJJH [ud + hā]
+ujJa:ujjh-a {%a.%} abandoning
+uttamarRa:uttama‡ṛṇa
+uttarozWa,°rOzWa:uttara‡oṣṭha
+udIcya:abnormal
+upayAcana:upa-yā{%c%}-ana
+upasti:úpa-sti ({%or%} -stí)
+upozaRa:upa‡oṣaṇa
+uzwf:úṣ-ṭṛ ({%or -trí%})
+U:abnormal
+U~:ūm̐
+Uh:ŪH ({%often ŭh%})
+fDak:ṛ́dh-ak ({%or%} ák)
+ekaka:eka-ká ({@akā
+ekayazwi:eka-yaṣṭi*
+ekESvarya:eka‡aiśvarya
+etaSa:éta-śa ({%sts. -s%}á)
+enap:abnormal
+E:*ai
+o:abnormal
+kakudruma:kaku[d]-druma
+kakzyA:kakṣyā̂
+kacawatapagajaqadaba:abnormal
+kanizWa:kán-iṣṭh-a ({%or%} -á)
+kam:KAM ({%no pres. base%})
+karizya:kariṣya [ḥ]
+kASmIrika:abnormal
+kila:kíla ({%V. sts.%} {@ā@}) {%ad. quidem%}
+kIdfS:kī-dríś
+kuRW:KUṆṬ
+kutra:kú-tra (-trā
+kf:KṚ (skṛ after upa
+kfpanILa:kṛpá-nīḷa
+kxptakeSanaKaSmaSru:abnormal
+kxpti:k{%lí%}p-ti ({%also%}-tí) {%f.%} coming about
+kruYc:krúñc ({%nm.%} {@kruṅ@})
+kzA:abnormal
+KA°:abnormal
+KUra:abnormal
+gamBIra:gambh-īrá = gabhīra: {@ā
+gavezaRa:gava‡eṣaṇa
+gavya:gáv-ya ({%or%} -yá)
+guRW:GUṆṬ
+gutsa:*gutsa
+gup:GUP ({%no pr. st.%}) guard
+gur:gur = gus
+glapsa:abnormal
+glAna:glā-na ({%pp.%} √ glai)
+cakreSa:cakra-īśa
+cawacaw:caṭa-ca{%t
+catasf:cátasṛ {%or%} catasṛ́
+cana:ca-ná ({%SV.%} caná)
+candrodaya:abnormal
+cala:cal-a {%a.%} moving
+cArcikya:*cārcik-ya
+citkAra:abnormal
+cuRwI:abnormal
+Canda:chánd-a {%or%} chand-á
+CucCUndara:chucchundara
+ja:ja (-°)
+jakz:abnormal
+jakz:JAKṢ [{%redupl. of%} has]
+jakzivAn:*jakṣ-i-vān
+jagat:já-g-at ({%pr. pt. redupl. fr.%} √ gā)
+jaNgala:*jaṅ-gal-a
+jani:ján-i ({%or%} {@ī@})
+janitf:ján-i-tṛ ({%or%} -tṛ́)
+janmarkza:janma‡ṛkṣa
+jAyaka:*jāya-ka
+juzwa:júṣ-ṭa ({%or%} -ṭá)
+jF:{%GRĪ%}
+jenya:jén-ia
+joNga:*joṅga
+jYAnecCAkriyASaktimat:abnormal
+jyezWa:jyā’‡iṣṭha ({%or%} {@á
+Qakkana:ḍhakka-na {%or%} {#°ma#} -ma
+tatra:tá-tra ({%V. also%} {@ā
+tAmrozWa:tāmra‡oṣṭha
+tittiri:tittíri ({%or%} í)
+tilodana:tila‡odana
+turAzAh:turā-ṣā́h ({%nm.%} {@-ṣā́ṭ; -sāh
+turIya:tur-īya ({%also%} tú- {%and%} -yá
+tedani:tedani ({%or%} {@î@})
+tyaj:TYAJ [(a)ti‡aj]
+trayodaSan:tráyo-daśan ({%or s%}án)
+trayodaSarca:trayodaśa‡ṛcá
+tripad:tri-pád ({%or%} trí-: {%strong st.%} {@-pād@})
+dakziRa:dákṣ-iṇa ({%also%} á)
+damBoli:abnormal
+daridra:dár-i-dra ({%also-í-dra%})
+darvi:dárvi ({%also%} {@ī@})
+darSa:dárś-a ({%or%} -á)
+dAruRa:dārú-ṇa ({%or%} á)
+dfkza:dṛk-ṣa (-°)
+dfS:dṛ́ś ({%nm.%} {@dṛk@})
+devatAgAra:devatā‡ā̆gāra
+dyotana:dyót-ana ({%or%} á)
+dramma:dramma <lang n="greek">(δραχμή)</lang>
+dravat:drav-át ({%pr. pt. of%} √ dru)
+dvAdaSan:dvā́-daśan ({%or%} án)
+dvApara:dvā-pára ({%or%} á)
+dvipad:dví-pad ({%or%} -pád: {%strong base%} {@-pād@})
+Danvadurga:abnormal
+DAnyAMSa:*dhānya‡aṃśa
+Di:dhi = adhi ({%in%} dhi-ṣṭhita
+Dyuzita:[a]dhy-uṣita
+na:abnormal
+nak:nák ({%only nm.%})
+napAt:ná-pāt ({%V. only in strong cases%})
+navadaSan:náva-daśan ({%or%} án)
+navan:návan ({%or%} án)
+nazwa:~naṣ-ṭa
+nazwi:~naṣ-ṭi
+nAgarI:*nāgarī
+nArada:nā́rada ({%or%} á)
+nAva:nāva = nau
+nid:abnormal
+nir:abnormal
+nirgatAKilakalmaza:abnormal
+nizpanda:niṣ-[s]panda
+nILa:nīḷá
+nyakta:ni‡âkta
+nyaYc:ni‡âñc
+nyarbuda:ni‡ârbuda
+nvE:n[ú]vaí
+paYcan:páñc-an ({%or%} {@-án@})
+paT:páth ({%weak base%}; {@pánthān
+panu:pan-ú ({%or%} -ū́)
+payozRI:paya[ḥ]‡uṣṇī
+paramarzi:parama‡ṛṣi
+paraHsahasra:páraḥ-sahasra ({%or%} rá)
+parAk:parāk (or {@ṅ@})
+parAyaRa:parā’‡ayaṇa
+parudvAra:*parud-vāra
+paro'kza:paró-[a]kṣa
+paro'varam:paro-(a)varám
+parozRih:para[ḥ]‡uṣṇih
+parmAqi:parmāḍi ({%or -nd%}i)
+paryARa:pari-[y]āṇa
+parzad:par-ṣad = pari-ṣad
+paSu:páś-u ({%or%} -ú
+paSca:*paś-cá
+pAkyA:pākyā̂
+pAna:pā’‡ana
+pASa:pā́ś-a {%m.%} [√ paś
+pAScAttya:pāścāt-tya ({%or%} -ya
+piMS:PIṂŚ {%and%} {#piMz#} PIṂṢ
+pibd:pibd [pi-p(a)d
+pIq:PĪḌ [pi-s(a)d
+puMScalI:pu{%ms-k%}al-ī́
+pumAMs:púmāṃs ({%strg. base%}; {%wk. base%}
+purauzRih:pura(ḥ)-uṣṇih
+puro'nuvAkyA:puro-(a)nuvākyā̂
+puz:puṣ (-°)
+puzwi:púṣ-ṭi ({%or -t%}í: {%RV.%})
+pftanAzah:pṛtanā-ṣáh ({%str. st.%} -ṣā́h)
+pfTak:abnormal
+potf:pó-tṛ ({%or%} -tṛ́)
+prauga:prá-üga
+praRava:pra-ṇáva ({%or%} á)
+pratIka:prátī-ka [prati‡ak-a
+praTama:pra-thamá [= pra-tama
+prapitAmaha:prá-pitāmaha ({%or%} á)
+prAcya:prāc-yâ ({%or%} yá)
+prADva:pra‡adhva [fore-journey]
+pruzvA:prúṣ-vā ({%or%} {@ā́@})
+prOQa:pra‡ūḍha
+prOQi:pra‡ūḍhi
+psaras:ps-ar-as [bh(a)s-ar-as]
+psu:psu [bh(a)s-u]
+psu:psu [bh(a)s-u]
+psuras:ps-úr-as [bh(a)s-ur-as]
+Par:PHAR [= SPHAR]
+PARwa:phāṇṭa [phāṇ(i)ta]
+PeRwa:pheṇṭa : {@-ka
+baD:abnormal
+barAsI:barāsī’
+barhizad:barhi[ḥ]-ṣád
+barhiHzad:barhiḥ-ṣad = barhi-ṣad; {@-ṣṭha@}
+bAlya:bā́l-ya ({%or%} -yâ)
+bAhya:bā́hya [{%fr.%} bahi(s)]
+buSa:buśa {%and%} {#buza#} buṣa
+bfhawwika:bṛha{%t-t%}ika
+brahmaRaspati:abnormal
+brahmaRvat:bráhmaṇ-vat ({%or%} -vát)
+brahmarzi:brahma‡ṛṣi
+brAhmaRAcCaMsin:brāhmaṇāt-śaṃs-ín
+BagIraTa:bhagī-ratha [bhagi-ratha
+BaNgi:bhaṅg-i ({%or%} {@ī@}) {%f.%} breaking; bend
+Bas:bhas = bhasman
+BA:BHĀ II.P. {@bhā́-ti
+BAwa:bhāṭa : {#°ka#} -ka
+BAm:BHĀM [{%dialectic form of%} bhram]
+Bikzu:bhikṣu ({%des. a.%})
+Bizaj:BHIṢAJ [(a)bhi-saj
+BUti:bhū́-ti ({%or%} -tí)
+BUma:abnormal
+BUmi:bhū́-mi ({%sts.%} {@ī@})
+Bfti:bhṛ-tí (ŚB. {%also%} bhṛ́-)
+Bo:abnormal
+macCarIra:mat-śarīra
+maYjari:mañj-ar-i ({%or%} ī)
+mawaka:maṭa-ka [{%Prākritic for%} mṛta-ka]
+maTan:math-an ({%only in.%} {@mathnā@})
+manotf:manó-tṛ ({%or%} -tṛ́)
+mantavya:man-távya ({%or%} yâ)
+mayUrI:mayū’r-ī
+mayoBu:mayo-bhú ({%or%} -bhū́)
+mazi:maṣ-i ({%or%} ī)
+mas:mas = mās
+masi:masi ({%or%} ī)
+mahacCabda:mahat-śabda
+mahartvij:mahā’‡ṛtvij ({%or%} íj)
+maharzi:mahā‡ṛṣi
+mahEtareya:mahā‡aitareya
+mAtura:mātur-a = mātṛ
+mAna:mā’‡ana
+mAnita:mAn-i-ta
+mAnuza:mā́nuṣ-a ({%or%} á)
+mAruta:mā́rut-a ({%or%} á: {%Br.%})
+mAlatI:mālatī ({%rarely%} i)
+mAsopavAsa:māsa‡upavāsa : {@-ka
+mikz:MIKṢ [{%des. of%} √ miś {%in%} miś-ra
+miTu:míth-u ({%or%} ū)
+mizwa:miṣ-ṭa [{%pp.%} = mṛṣṭa]
+mI:mī {%occurs in some forms of%} √ mā
+muhu:múh-u ({%or%} -ú)
+mUrti:mū’r-ti
+mUla:mū́l-a [= mū́r-a
+mfkaRqa:mṛkaṇḍa ({%also%} u)
+mfkz:MṚK-Ṣ [{%der. of%} √ mṛj]
+mfcCakawika:mṛd-śakaṭ-ika
+mfR:MṚṆ [{%fr.%} mṛ-ṇā
+meDapati:médha-pati ({%or%} medhá-)
+meLi:meḷí
+yakan:abnormal
+yakft:yák-ṛt ({%nm. &%} °-)
+yajYa:ya{%g-ñ%}á
+yatra:yá-tra ({%V. sts.%} ā́)
+yaTarcam:yathā‡ṛcam
+yadi:yád-i ({%V. also%} {@ī@} {%metr.%})
+yayi:ya-y-í ({%or%} ī́)
+yavanAnI:*yavan-ānī
+yazwf:yáṣ-ṭṛ́ ({%or -trí%})
+yAcYA:yā{%k-ñ%}ā́
+yAtayAma:yātá-yāma : {#°n#} -n
+yAna:yā’‡ana
+yAvacCaktitas:yāvat-śakti-tas
+yuC:YU-CH [{%pr. base of%} √ ¤2.¤ yu]
+yup:YUP ({%V.
+yuvati:yuva-tí ({%or%} ī)
+yUTa:yū-thá [union: √ ¤1.¤ yu]
+raMh:RAṂH [= RAÑGH]
+rakz:RAK-Ṣ [{%der. of%} √ rak
+raGu:ragh-ú [√ raṅgh = raṃh]
+rasAsvAda:rasa‡āvāda
+rA:abnormal
+rAmyA:rā́m-yā ({%or%} ā̂)
+rip:RIP ({%RV.%}; {%rare
+rizwi:ṛ́ṣ-ṭi
+ruci:rúc-i ({%or%} í)
+ruD:RUDH [= ¤2.¤ RUH]
+[ruh:RUH = {#ruD#} RUDH
+rOdra:raúdra ({%or%} á)
+lam:LAM [= √ ram]
+lamb:LAMB [{%later form of%} √ ramb]
+lip:LIP VI. {@limpá@} [{%later form of%} √ rip]
+lih:LIH [{%later form of%} √ rih]
+luRW:LUṆṬ
+lohita:lóh-ita [{%later form of%} rohita]
+vajrivas:abnormal
+vataMsa:[a]va-taṃsa
+vadAnya:[a]va-dān-ya
+vaDU:vadh-ū’
+van:van (= vana
+varayuvati:vara-yuvati ({%or%} {@ī@})
+varzya:várṣ-ya ({%yv.
+valaBi:valabhi ({%or more commonly%} {@ī@})
+vali:val-i ({%or%} ī)
+vallari:vallari ({%or%} {@ī@})
+valli:valli ({%rare%})
+vas:VAS ({%RV.
+vasantA:vasántā ({%or%} ā́)
+vah:vah ({%only%} -°
+vARArasI:vāṇārasī = vārāṇasī
+vAta:vā́-ta [{%pp.%} √ ¤1.¤ vā
+vAma:vā-má [√ ¤3.¤ vā]
+vidAna:vid-āna ({%or%} á)
+vidyeSa:vidyā‡īśa {%m.%} lord of knowledge
+viD:vidh (√ vyadh)
+viBaktf:ví-bhaktṛ ({%w. ac.%}) {%or%} tṛ́ ({%w. g.%})
+viSAKa:ví-śākha ({%AV. also-s%}ā́kha)
+viSvaha:viśvá-ha ({%or%} ā)
+vizuvat:viṣŭ-vat
+vizw:VIṢ-Ṭ [{%prob. der. of%} √ viś]
+vfzala:vṛṣa-lá ({%or%} vṛ́ṣa-la
+vfzwi:vṛṣ-ṭí ({%RV.
+vfzRi:vṛ́ṣ-ṇi ({%or n%}í)
+vfh:VṚH {%or%} BṚH
+veNgi:veṅgi ({%or%} ī)
+veRu:véṇu ({%or%} ú)
+veditf:véd-i-tṛ ({%or%} -tṛ́
+vezaRa:véṣ-aṇa ({%or%} á)
+vEkakzika:vaikakṣ-ika ({%or%} -ya)
+vEkaNkata:vaikaṅkata ({%or%} á)
+vEjayanta:abnormal
+voQf:vóḍhṛ ({%or ri%})
+vopadeva:abnormal
+vo|um:voḷhum
+vyaj:VI‡AJ = {#vIj#} VĪJ
+vyazwi:vi‡âṣṭi
+vyAqi:vyāḍ-i ({%or%} ḷi)
+vyUQa:vi‡ūḍha ({%V.%} {@-ūṭhá@})
+vratati:vratáti ({%sts.%} ī)
+vraSc:abnormal
+Sakan:śák-an ({%or%} -án)
+SanEs:śánais ({%RV.%}
+Sama:abnormal
+SaMBu:śaṃ-bhú ({%or%} ū́)
+SaravyA:śaravyā̂
+Salpa:śalpa : {#°ka#} -ka
+Sazkuli:śaṣkuli ({%or%} {@ī@})
+SA:ŚĀ III. ({%RV.%}) {@śiśā@}
+SAkapArTiva:*śāka-pārthiva
+SAKowa:śākhoṭa : {#°ka#} {@-ka
+Simbi:śimbi ({%or%} {@ī@})
+Sir:ŚIR (= √ ¤2.¤ śṛ)
+SiSvi:abnormal
+Sis:ŚIS ({#Siz#} ŚIṢ)
+SudDodana:śuddha‡odana
+SevfDa:śé[va]-vṛdha ({%or%}á¹)
+Scar:ŚCAR (= CAR)
+Srat:śrát {%or%} {#Srad#} śrád
+SraTAya:śrathā-ya ({%RV.%})
+SraddaDAnatA:śrad-dadhāna-tā {%f.%} faith; {@-vat
+SrI:ŚRĪ (= ŚRĀ)
+SrI:ŚRĪ (= ŚRI)
+Sru:ŚRU = {#sru#} SRU
+Sruz:abnormal
+Sruzwi:śrúṣ-ṭi ({%AV.%}; {@-ṭí@}
+Sreyo'BikANkzin:śreyo-(a)bhikāṅkṣin
+Srotf:śró-tṛ ({%w. ac.%}) {%or%} {@-tṛ@} ({%w. g.%})
+SlizwaparaMparitarUpaka:abnormal
+SvA:ŚVĀ {%or%} {#Svi#} ŚVI
+za:abnormal
+zaLUnA:ṣaḷ-ūnā
+zWu:ṢṬHU (= √ ṣṭhīv)
+saG:SAGH [= SAH]
+saccandrikA:sat-candrikā
+sacCAstra:sat-śāstra
+sawAlu:saṭālu = śalāṭu
+saMqIvin:sa{%m-d%}īvin
+sat:[a]s-át
+satrAYc:satrā’‡añc
+sadAnanda:sadā-ānanda
+sannamusala:abnormal
+saptarca:sapta‡ṛcá
+saB:SABH = {#sah#} SAH
+samAna:samāná [{%fr.%} sama]
+saMBava:saṃ-bhavá ({%VS.%}
+saraw:saráṭ ({%or%} h ?)
+saropAnta:sara[ḥ]‡upānta
+saSc:SAŚC [{%contracted fr.%} sa-s(a)c: √ sac]
+sANga:sá‡aṅga ({%or%} á)
+sAraNga:sāráṅga ({%or%} á
+sAh:sāh (-°)
+su:SU (= √ ¤1.¤ sū)
+su:SU (= √ ¤2.¤ sū)
+su:sú ({%in V. also%} sū́)
+suganDi:su-gándh-i ({%or%} {@í@})
+suzvaya:suṣvaya [{%den. fr.%} súṣvi
+sUr:sū́r = {#svar#} su‡â{@r@}
+sUrta:sū’r-ta
+sf:ŚṚ
+sfj:ŚṚJ VI. {@sṛjá@}
+sfRI:sṛ́ṇī ({%or%} ī́)
+sfp:ŚṚP
+so:abnormal
+sOparRa:saúparṇa ({%sts. also%} á)
+sOmya:saum-yá ({%AV. also%} saúm-)
+sTAna:sthā’‡ana
+snAvan:snā́-van ({%or%}) -ván)
+snIhiti:snī’h-iti
+spUrD:SPŪRDH [{%collateral form of%} spṛdh
+spfh:SPṚH [{%collateral of%} SPṚDH]
+srA:SRĀ ({%cp.%} √ śrā)
+svar:svâr ({%in YV. also%} {#suvar#} súvar)
+svaraMkfta:abnormal
+svAti:svātí ({%or%} ī́)
+svEra:sva‡īra
+svErin:sva‡īr-in
+haragalagaralatamAla:abnormal
+hasa:hás-a ({%or%} á)
+hArd:abnormal
+hiMs:HIṂS [{%anomolous des. of%} √ han]
+huhu:huhŭ
+hUrC:HŪR-CH [{%prob. der. of%} √ hvṛ]
+hfcCaya:hṛd-śaya
+asOnAman:abnormal
+UrDvANguli:abnormal
+kAryavinimaya:abnormal
+kAlidAsa:abnormal
+nyAyAropitavikrama:abnormal
+prakz:PRAK-Ṣ = {#praC#} PRACH
+praBaNga:pra-bhaṅgá : {%line%} ¤8¤
+pravidvas:abnormal
+barh:abnormal
+yajYArTam:abnormal
diff --git a/deva_iast_comp/readme.txt b/deva_iast_comp/readme.txt
new file mode 100644
index 0000000..afb72dc
--- /dev/null
+++ b/deva_iast_comp/readme.txt
@@ -0,0 +1,12 @@
+deva_iast_comp
+
+This directory contains programs to analyze the data in
+https://github.com/sanskrit-lexicon/csl-orig/issues/628.
+
+It is intended also as a tutorial on Python programming.
+
+data.txt  This is a text file containing the data in the first comment of
+the issue 628.
+
+step0  Contains first program, to read the data.txt file, and write
+       the lines therin to another file. See step0/readme.txt for more info.
diff --git a/deva_iast_comp/step0/readme.txt b/deva_iast_comp/step0/readme.txt
new file mode 100644
index 0000000..a34e5c2
--- /dev/null
+++ b/deva_iast_comp/step0/readme.txt
@@ -0,0 +1,39 @@
+step0/readme.txt
+
+This readme.txt file is just a text file, written as a guide to what is in the
+step0 directory.
+
+# ------------------------------------
+readwrite.py  First python program, designed to read the lines of data.txt
+  and write the upper-cased lines to another file.
+  Usage:
+python readwrite.py ../data.txt readwrite.txt
+
+Suggestions for study:
+1.  Study the program - start at the bottom  (at 'if __name__=="__main__":').
+  Pay particular attention to the indentation, as it is an important
+  detail peculiar to Python.
+  When you get to 'lines = read_lines(filein)', go back up to 'def read_lines'
+  to see what the read_lines 'function' is doing.
+  Similarly review the rest of the 'main' part.
+2. Run the program, as indicated in the 'usage' comment above.
+   Look at 'readwrite.txt' -  is it as you expected?
+3. Make another program (you choose the name), which reads 'readwrite.txt'
+   and changes all letters to lower case. Then run the program.
+4. When you're done, push the directory.
+
+#-------------------------------------------
+'temp' files.
+Look at the .gitignore file in the MD directory top level.
+The 'temp*' line means that any file (or directory) whose name starts with
+'temp' will NOT be tracked by git.  Such files will be available on your
+machine, but will be ignored when you push.
+This is a good way to make small experiments that are meaningful for you
+but that might not be useful to other repository users.
+
+Conversely, files which you
+do want to share with others should have names that do not start with 'temp'.
+
+You can always do a 'git status' after 'git add' but before 'git commit' to
+see which files git is tracking.
+
diff --git a/deva_iast_comp/step0/readwrite.py b/deva_iast_comp/step0/readwrite.py
new file mode 100644
index 0000000..5aa4bc5
--- /dev/null
+++ b/deva_iast_comp/step0/readwrite.py
@@ -0,0 +1,74 @@
+# coding=utf-8
+"""readwrite.py
+   
+"""
+from __future__ import print_function
+import sys,re,codecs
+
+# def f(x,y,z):  that's the way Python function definitions start
+def read_lines(filein):
+ # Notice the indentation
+ # there's a lot packed into the next line.
+ # We could say:
+ #  open file named filein for reading. The file is encoded as utf-8.
+ #  Use the variable 'f' for reading from the file. 'f' could be
+ #  called the 'file handle'.
+ with codecs.open(filein,"r","utf-8") as f:
+  # Notice the further indentation
+  # Read every line in the file, and strip from the end of each
+  # line the line-ending characters '\r\n'
+  # And, add each stripped line into the Python list named 'lines'
+  lines = [line.rstrip('\r\n') for line in f]
+ # Notice we have gone back to 1 character of indentation (same as 'with')
+ # print to the 'console' a message indicating how many lines were read
+ print(len(lines),"lines read from",filein)
+ # the function returns the list of lines
+ return lines
+
+# this adjustlines function capitalizes each line
+def adjustlines(lines):
+ newlines = []  # start with an empty list, in which the new lines will be put
+ # adjust each line in a python 'for loop'
+ 
+ for line in lines:
+  # we know, from the way read_lines was constructed, that each element
+  # in lines represents a line of the text file used as input ('filein')
+  # As such, it is a python 'str' (for 'string'). There is a builtin way to
+  # convert strings to upper case
+  newline = line.upper()
+  # We want to add the new line to our list of new lines.
+  # 'append' is the way to do that
+  newlines.append(newline)
+ # we're done with the for loop, so we go back one level of indentation
+ # We need to return the newlines object that this function computed
+ return newlines
+ 
+def write_lines(fileout,lines):
+ # Note we call this function as 'write_lines(fileout,newlines)'.
+ # In this function, the function parameter 'lines' will, when
+ # called, have the value newlines.
+ # open the file, but this time for 'writing'
+ with codecs.open(fileout,"w","utf-8") as f:
+  # write each line using a for loop
+  for line in lines:
+   # we will add the 'newline' line break character at the end of the line
+   f.write(line+'\n')
+ print(len(lines),"lines written to",fileout)
+ # This function doesn't explicitly return anything.
+
+if __name__=="__main__":
+ # First input argument: path to input text file
+ filein = sys.argv[1]
+ # Second input argument: path to output text file
+ fileout = sys.argv[2] # word frequency
+ # Call function read_lines to get all the input lines into
+ #  a python list 'lines'
+ lines = read_lines(filein)
+ # Call function adjustlines to do something to each line
+ # Result is the list newlines
+ newlines = adjustlines(lines)
+ # write the list of new lines to fileout
+ write_lines(fileout,newlines)
+ # That's all this little program does
+
+