為什么出現索引超出范圍錯誤？

Question

def improve_fight_song(title):
    Tech_file = open("RamblinWreck.txt","r")
    myfile= open("ImprovedFightSong.txt","w")
    lines = Tech_file.readlines()

#Lets find all of the engineer cases.
    for s in range(len(lines)):
        if "engineer" in lines[s]:
           z = lines[s].replace("engineer","programmer")
           myfile.write(z)



    myfile.close()

improve_fight_song("kjhk")

我似乎無法弄清楚為什么我在這里超出范圍。 我試圖通過行的長度使for循環有趣，它只是所有行的列表（以字符串為單位），但這也不起作用。 下面是實際的錯誤信息

追溯（最近一次通話最近）：文件“ /Users/treawethington/Documents/HW6.py”，第16行，在perform_fight_song（“ kjhk”）中，文件“ /Users/treawethington/Documents/HW6.py”，第8行，在如果第幾行中的“工程師”，則為perfect_fight_song：IndexError：列表索引超出范圍

Answer 1

當我測試您更新的代碼時，它運行良好，但是我認為您正在尋找的是：

def improve_fight_song():
    tech_file = open("RamblinWreck.txt", "r")
    myfile = open("ImprovedFightSong.txt", "w")
    lines = tech_file.readlines()

    # Lets find all of the engineer cases.
    for line in lines:  # no need for range here
        if "an engineer" in line:
            myfile.write(line.replace("an engineer", "a programmer"))
        else:
            myfile.write(line)

    myfile.close()
    tech_file.close()  # close this file as well


improve_fight_song()

當這是內容RamblinWreck.txt和這個是內容ImprovedFightSong.txt運行后HW6.py 。

Answer 2

通常，您不應該按索引遍歷行列表。 只需使用：

for s in lines:
    if 'engineer' in s:
         z = s.replace('engineer', 'programmer')

請注意，您的原始代碼僅寫入已更改的行。

除了遍歷所有行，您還可以替換文件的全部內容：

with open("RamblinWreck.txt","r") as infile:
    text = infile.read()

outtext = text.replace('engineer', 'programmer')

with open("ImprovedFightSong.txt","w") as outfile:
    outfile.write(outtext)