Yesterday when I was young
昨日當(dāng)我年少輕狂
The taste of life was sweet
生命的滋味是甜的
As rain upon my tongue

#將文件讀取到內(nèi)存中
with open("./fileread.txt","r",encoding="utf-8") as f:
 lines = f.readlines() 
#寫的方式打開文件
with open("./fileread.txt","w",encoding="utf-8") as f_w:
 for line in lines:
  if "taste" in line:
   #替換
   line = line.replace("taste","tasting")
  f_w.write(line)

#文本內(nèi)容
Yesterday when I was young
昨日當(dāng)我年少輕狂
The taste of life was sweet
生命的滋味是甜的
As rain upon my tongue
taste
taste
taste
taste

#定義一個函數(shù)，帶有4個參數(shù)
#x 表示要更新的文件名稱
#y 表示要被替換的內(nèi)容
#z 表示 替換后的內(nèi)容
#s 默認(rèn)參數(shù)為 1 表示只替換第一個匹配到的字符串
# 如果參數(shù)為 s = 'g' 則表示全文替換
def string_switch(x,y,z,s=1):
 with open(x, "r", encoding="utf-8") as f:
  #readlines以列表的形式將文件讀出
  lines = f.readlines()
 
 with open(x, "w", encoding="utf-8") as f_w:
  #定義一個數(shù)字，用來記錄在讀取文件時在列表中的位置
  n = 0
  #默認(rèn)選項，只替換第一次匹配到的行中的字符串
  if s == 1:
   for line in lines:
    if y in line:
     line = line.replace(y,z)
     f_w.write(line)
     n += 1
     break
    f_w.write(line)
    n += 1
   #將剩余的文本內(nèi)容繼續(xù)輸出
   for i in range(n,len(lines)):
    f_w.write(lines[i])
  #全局匹配替換
  elif s == 'g':
   for line in lines:
    if y in line:
     line = line.replace(y,z)
    f_w.write(line)

string_switch("fileread.txt","taste","tasting")
 
#結(jié)果
Yesterday when I was young
昨日當(dāng)我年少輕狂
The tasting of life was sweet
生命的滋味是甜的
As rain upon my tongue
taste
taste
taste
taste

string_switch("fileread.txt","taste","tasting","g")
 
#結(jié)果
Yesterday when I was young
昨日當(dāng)我年少輕狂
The tasting of life was sweet
生命的滋味是甜的
As rain upon my tongue
tasting
tasting
tasting
tasting