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Computational Physics Laboratory���Python scripting

LECTURE 5 PRACTICE ON SCRIPTING

Outline •  Practice on exam tests

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Python

file_input = open("input-base", "r")str_input = file_input.read()file_input.close()for i in range(10): modified_input = str_input.replace("cut",str(i+1)) new_input = open("input"+str(i+1), "w") new_input.write(modified_input) new_input.close()

Open the file Put its content in a string Close the file Loop on i: Modify the string with .replace method Open i-th output file Write in the output file Close the output file

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Python

import sys

if len(sys.argv) < 3: print("Usage: python svolgimento.py word text_file") sys.exit(2)

word = sys.argv[1]textfile = sys.argv[2]f = open(textfile, "r")content = f.read()f.close()found = Falseif word in content: print(word + " is in " + textfile) found = True

if not found: print(word + " is not in " + textfile)

Note: Use sys module to pass the string to search for and the file

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Python

import os

list_res = [x for x in os.listdir() if x.endswith(".res")]for filename in list_res: fin = open(filename, "r") fileout = os.path.splitext(filename)[0]+".dat" fout = open(fileout, "w") Nlines = 0 for line in fin.readlines(): Nlines += 1 if Nlines >= 6 and Nlines <=105: fout.write(line) fin.close() fout.close()

Note 2: Used a list-comprehension to create a list with .res files in the script directory

Note 1: import osf = "nomefile.txt"splitted = os.path.splitext(f)print(type(splitted))print(splitted)

Result: >>><class 'tuple'>('nomefile', '.txt')>>>

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Python

import fnmatchimport ospattern = "*.tex"

files = os.listdir('./lettere')for name in files: if fnmatch.fnmatch(name, pattern): dirname = name.strip(".tex") os.mkdir(dirname) os.system("cp lettere/" + name + " " + dirname + "/" + name)

os.chdir(dirname) file_letter = open(name, "r") letter = file_letter.read() file_letter.close() os.system("rm " + name) modified_letter = letter.replace("15","04")

modified_letter = modified_letter.replace("03","05") new_letter = open(name, "w") new_letter.write(modified_letter) new_letter.close() os.system("latex " + name) os.system("dvipdf " + dirname + ".dvi") os.system("rm " + name)

os.system("rm " + dirname + ".dvi") os.system("rm " + dirname + ".aux") os.system("rm " + dirname + ".log") os.chdir("../")

import fnmatchimport os

for file in os.listdir(): if fnmatch.fnmatch(file, '*.txt'): print(file)

Result example: >>>textfile.txt>>>

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Python

import osos.chdir("./dati")list_pdat = [x for x in os.listdir() if x.endswith(".dat")]file_sez = open("xsec.res", "w") #il file deve contenere le prime colonne di ogni file.dat

sezioni = [] #creo una lista vuota, ogni elemento sarà una riga del file "xsec.res”readfile = 0for filename in list_pdat: #ciclo sui files

fin = open(filename, "r") fileout = os.path.splitext(filename)[0]+".res" fout = open(fileout, "w") readline = 0

for line in fin.readlines(): #ciclo sulle linee nel file list_data = line.split() if readfile==0: # N.componenti = N.linee dei files.dat

sezioni.append(list_data[0]) #la lista contiene la prima colonna del file else: #ho già la lista con le corrette dimensioni sezioni[readline] += "\t"+list_data[0] readline += 1

stringa = "" for i in range(len(list_data)): if i>0: stringa += list_data[i]+"\t"

fout.write(stringa+"\n") readfile = 1 fin.close()

fout.close() os.system("rm "+filename)for i in range(readline): file_sez.write(sezioni[i]+"\n")

file_sez.close()

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Python

import osimport sys

def nonblank_lines(f): for l in f: line = l.rstrip() if line: yield line

if len(sys.argv) < 2: print("Pass me a process, please!") sys.exit(2)

process = sys.argv[1]os.system("ps -xc > processes.txt")

file_proc = open("processes.txt", "r")found = Falsefor line in nonblank_lines(file_proc): if process in line: info = line.split(" ") print("The PID of process: " + process + " is: " + info[2]) found = True

if not found: print("There is no process called: " + process)os.system("rm processes.txt")file_proc.close()

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Python

def nonblank_lines(f): for l in f: line = l.rstrip()

if line: yield linetitles = []names = []fnames = []Nguys = 0

file_names = open("elenco.txt", "r")for line in nonblank_lines(file_names): attribute = line.split(" ") titles.append(attribute[0]) names.append(attribute[1]) fnames.append(attribute[2])

Nguys += 1file_letter = open("lettera.txt", "r")letter = file_letter.read()file_letter.close()for i in range(Nguys): modified_letter = letter.replace("FAMILYNAME",fnames[i]) modified_letter = modified_letter.replace("NAME",names[i])

modified_letter = modified_letter.replace("TITLE",titles[i]) new_letter = open(fnames[i]+"_LETTER.txt", "w") new_letter.write(modified_letter) new_letter.close()