Python - 如何用另一个字符串替换文本文件中的某一行？
Python - How do you replace a certain line in a text file with another string?
我正在使用 python 创建一个测验程序。一共有三个文本文件，一个用于输出问题（作品），一个用于检查用户是否输入正确（作品），一个用于更新掌握情况。后者不起作用。一道题答对三遍就掌握了。我想从文本文件更新掌握度，从零到一（依此类推）。
当我 运行 我的程序时，它用 1 替换了第一行，但是它下面的两个 0 丢失了，因此我收到索引超出范围错误。我愿意尝试其他方法。
这是我试图将下面的代码实现到我自己的程序中的代码：
with open('stats.txt', 'r') as file:
# read a list of lines into data
data = file.readlines()
print(data)
print("Your name: " + data[0])
x = "0"
# now change the 2nd line, note that you have to add a newline
data[1] = x + "\n"
# and write everything back
with open('stats.txt', 'w') as file:
file.writelines(data)
我的程序：
question_answered = 0 # sets number of questions answered to zero
lineq = 6 # sets the number of lines to output from questions.txt
linea = 0 # sets the number of linea to read from answers.txt
with open("questions.txt", "r") as q:
with open("answers.txt", "r") as a:
answer_lines = a.readlines()
while question_answered != 3:
question_answered += 1
for i in range(lineq):
line2 = (q.readline())
print(line2)
response = input("answer:")
if response not in answer_lines[linea]:
print("incorrect")
mastery = (update_mastery[linea])
mastery = int(mastery)
if mastery < 1:
print("mastery", mastery)
else:
mastery -= 1
print("mastery", mastery)
else:
print("correct")
with open("mastery.txt", "r") as m:
update_mastery = m.readlines()
mastery = update_mastery[linea]
mastery = int(mastery) + 1
mastery = str(mastery)
update_mastery[linea] = mastery + "\n"
with open('mastery.txt', 'w') as m:
m.writelines(update_mastery[linea])
linea += 1
questions()
questions.txt:
1)Define isotope
[A]Atoms of the same element with same number of protons and a different number of neutrons
[B]Atoms of the different element with same number of protons and a different number of neutrons
[C]Atoms of the same element with same number of neutrons and a different number of protons
[D]Atoms of the same element with same number of protons and a different number of electrons
2)Name the type of decay that occurs when, they have too many neutrons
[A]Gamma Radiation
[B]Alpha Decay
[C]Beta Plus Decay
[D]Beta Minus Decay
3)Define Coulomb
[A]1 coulomb is the quantity of charge carried past a given point if a steady current of 1 amp flows for 1 second
[B]1 coulomb is the quantity of charge carried past a given point if a steady voltage of 1 volts per 1 second
[C]1 coulomb is the quantity of current carried past a given point if a steady voltage of 1 volts per 1 second
[D]1 coulomb is the rate of flow of charge
answers.txt:
A
D
A
mastery.txt:
0
0
0
我相信使用存储在 pickle 中的字典来跟踪掌握程度会更容易。它使得处理程序的状态变得非常容易，并且修改起来要快得多。
为了快速回答，我会像这样加载泡菜：
"""
We are loading the pickled mastery values by checking if the pickle file exists.
If it doesn't we define a default mastery level
"""
try:
with open("mastery.p", "rb") as mastery_file:
mastery = pickle.load(mastery_file)
except FileNotFoundError:
mastery = {
"1: Define isotope": 0,
"2: Name the type of decay that occurs when, they have too many neutrons": 0,
"3: Define Coulomb": 0,
}
然后您可以将 mastery 用作常规字典并相应地修改值。完成后，可以再次保存pickle中的mastery状态：
def save():
with open("mastery.p", "wb") as m:
pickle.dump(mastery, m)
现在整个程序：
import pickle
"""
Here we defining the quesions and choices in a dictionary, but you could
load them from a normal text file, json file, or a pickle.
The questions are the keys to choices.
"""
q_and_a = {
"1: Define isotope": [
"[A]Atoms of the same element with same number of protons and a different number of neutrons",
"[B]Atoms of the different element with same number of protons and a different number of neutrons",
"[C]Atoms of the same element with same number of neutrons and a different number of protons",
"[D]Atoms of the same element with same number of protons and a different number of electrons",
],
"2: Name the type of decay that occurs when, they have too many neutrons": [
"[A]Gamma Radiation",
"[B]Alpha Decay",
"[C]Beta Plus Decay",
"[D]Beta Minus Decay",
],
"3: Define Coulomb": [
"[A]1 coulomb is the quantity of charge carried past a given point if a steady current of 1 amp flows for 1 second",
"[B]1 coulomb is the quantity of charge carried past a given point if a steady voltage of 1 volts per 1 second",
"[C]1 coulomb is the quantity of current carried past a given point if a steady voltage of 1 volts per 1 second",
"[D]1 coulomb is the rate of flow of charge",
],
}
"""
The answers have been defined with the same scheme as the questions
Once again, you could load these from a file or add them as the last
item in the q_and_a and filter them out when giving the questions.
"""
answers = {
"1: Define isotope": "a",
"2: Name the type of decay that occurs when, they have too many neutrons": "b",
"3: Define Coulomb": "a",
}
"""
We are loading the pickled mastery values by checking if the pickle file exists.
If it doesn't we define a default mastery level
"""
try:
with open("mastery.p", "rb") as mastery_file:
mastery = pickle.load(mastery_file)
except FileNotFoundError:
mastery = {
"1: Define isotope": 0,
"2: Name the type of decay that occurs when, they have too many neutrons": 0,
"3: Define Coulomb": 0,
}
# Here, we are iterating over every question each session
def show_questions(q, choices):
print(f"{q}:") # Show the question
print("\n".join(choices)) # Show the choices
answer = input("You answer: ") # wait for answer
if answer.lower() != answers[q]: # convert to lowercase (to match answerkey)
print(f"wrong, answer is {answers[q]}")
mastery[q] -= 1
print(f"Your mastery decreased to {mastery[q]}\n")
return False
else:
print("Correct!")
mastery[q] += 1
print(f"Your mastery increased to {mastery[q]}\n")
return True
def save():
with open("mastery.p", "wb") as m:
pickle.dump(mastery, m)
def loop_all():
"""
Loops through all qustions once
"""
for q, choices in q_and_a.items():
show_questions(q, choices)
save()
def for_mastery(max_level=3):
"""
Loops through each question till mastery is reached
Mastery can be adjusted by passing it as an argument
"""
for q, m in mastery.items():
print(m)
choices = q_and_a[q]
while m < max_level:
passed = show_questions(q, choices)
if passed:
m += 1
else:
m -= 1
save()
print("mastered!\n")
for_mastery()
我正在使用 python 创建一个测验程序。一共有三个文本文件，一个用于输出问题（作品），一个用于检查用户是否输入正确（作品），一个用于更新掌握情况。后者不起作用。一道题答对三遍就掌握了。我想从文本文件更新掌握度，从零到一（依此类推）。
当我 运行 我的程序时，它用 1 替换了第一行，但是它下面的两个 0 丢失了，因此我收到索引超出范围错误。我愿意尝试其他方法。
这是我试图将下面的代码实现到我自己的程序中的代码：
with open('stats.txt', 'r') as file:
# read a list of lines into data
data = file.readlines()
print(data)
print("Your name: " + data[0])
x = "0"
# now change the 2nd line, note that you have to add a newline
data[1] = x + "\n"
# and write everything back
with open('stats.txt', 'w') as file:
file.writelines(data)
我的程序：
question_answered = 0 # sets number of questions answered to zero
lineq = 6 # sets the number of lines to output from questions.txt
linea = 0 # sets the number of linea to read from answers.txt
with open("questions.txt", "r") as q:
with open("answers.txt", "r") as a:
answer_lines = a.readlines()
while question_answered != 3:
question_answered += 1
for i in range(lineq):
line2 = (q.readline())
print(line2)
response = input("answer:")
if response not in answer_lines[linea]:
print("incorrect")
mastery = (update_mastery[linea])
mastery = int(mastery)
if mastery < 1:
print("mastery", mastery)
else:
mastery -= 1
print("mastery", mastery)
else:
print("correct")
with open("mastery.txt", "r") as m:
update_mastery = m.readlines()
mastery = update_mastery[linea]
mastery = int(mastery) + 1
mastery = str(mastery)
update_mastery[linea] = mastery + "\n"
with open('mastery.txt', 'w') as m:
m.writelines(update_mastery[linea])
linea += 1
questions()
questions.txt:
1)Define isotope
[A]Atoms of the same element with same number of protons and a different number of neutrons
[B]Atoms of the different element with same number of protons and a different number of neutrons
[C]Atoms of the same element with same number of neutrons and a different number of protons
[D]Atoms of the same element with same number of protons and a different number of electrons
2)Name the type of decay that occurs when, they have too many neutrons
[A]Gamma Radiation
[B]Alpha Decay
[C]Beta Plus Decay
[D]Beta Minus Decay
3)Define Coulomb
[A]1 coulomb is the quantity of charge carried past a given point if a steady current of 1 amp flows for 1 second
[B]1 coulomb is the quantity of charge carried past a given point if a steady voltage of 1 volts per 1 second
[C]1 coulomb is the quantity of current carried past a given point if a steady voltage of 1 volts per 1 second
[D]1 coulomb is the rate of flow of charge
answers.txt:
A
D
A
mastery.txt:
0
0
0
我相信使用存储在 pickle 中的字典来跟踪掌握程度会更容易。它使得处理程序的状态变得非常容易，并且修改起来要快得多。
为了快速回答，我会像这样加载泡菜：
"""
We are loading the pickled mastery values by checking if the pickle file exists.
If it doesn't we define a default mastery level
"""
try:
with open("mastery.p", "rb") as mastery_file:
mastery = pickle.load(mastery_file)
except FileNotFoundError:
mastery = {
"1: Define isotope": 0,
"2: Name the type of decay that occurs when, they have too many neutrons": 0,
"3: Define Coulomb": 0,
}
然后您可以将 mastery 用作常规字典并相应地修改值。完成后，可以再次保存pickle中的mastery状态：
def save():
with open("mastery.p", "wb") as m:
pickle.dump(mastery, m)
现在整个程序：
import pickle
"""
Here we defining the quesions and choices in a dictionary, but you could
load them from a normal text file, json file, or a pickle.
The questions are the keys to choices.
"""
q_and_a = {
"1: Define isotope": [
"[A]Atoms of the same element with same number of protons and a different number of neutrons",
"[B]Atoms of the different element with same number of protons and a different number of neutrons",
"[C]Atoms of the same element with same number of neutrons and a different number of protons",
"[D]Atoms of the same element with same number of protons and a different number of electrons",
],
"2: Name the type of decay that occurs when, they have too many neutrons": [
"[A]Gamma Radiation",
"[B]Alpha Decay",
"[C]Beta Plus Decay",
"[D]Beta Minus Decay",
],
"3: Define Coulomb": [
"[A]1 coulomb is the quantity of charge carried past a given point if a steady current of 1 amp flows for 1 second",
"[B]1 coulomb is the quantity of charge carried past a given point if a steady voltage of 1 volts per 1 second",
"[C]1 coulomb is the quantity of current carried past a given point if a steady voltage of 1 volts per 1 second",
"[D]1 coulomb is the rate of flow of charge",
],
}
"""
The answers have been defined with the same scheme as the questions
Once again, you could load these from a file or add them as the last
item in the q_and_a and filter them out when giving the questions.
"""
answers = {
"1: Define isotope": "a",
"2: Name the type of decay that occurs when, they have too many neutrons": "b",
"3: Define Coulomb": "a",
}
"""
We are loading the pickled mastery values by checking if the pickle file exists.
If it doesn't we define a default mastery level
"""
try:
with open("mastery.p", "rb") as mastery_file:
mastery = pickle.load(mastery_file)
except FileNotFoundError:
mastery = {
"1: Define isotope": 0,
"2: Name the type of decay that occurs when, they have too many neutrons": 0,
"3: Define Coulomb": 0,
}
# Here, we are iterating over every question each session
def show_questions(q, choices):
print(f"{q}:") # Show the question
print("\n".join(choices)) # Show the choices
answer = input("You answer: ") # wait for answer
if answer.lower() != answers[q]: # convert to lowercase (to match answerkey)
print(f"wrong, answer is {answers[q]}")
mastery[q] -= 1
print(f"Your mastery decreased to {mastery[q]}\n")
return False
else:
print("Correct!")
mastery[q] += 1
print(f"Your mastery increased to {mastery[q]}\n")
return True
def save():
with open("mastery.p", "wb") as m:
pickle.dump(mastery, m)
def loop_all():
"""
Loops through all qustions once
"""
for q, choices in q_and_a.items():
show_questions(q, choices)
save()
def for_mastery(max_level=3):
"""
Loops through each question till mastery is reached
Mastery can be adjusted by passing it as an argument
"""
for q, m in mastery.items():
print(m)
choices = q_and_a[q]
while m < max_level:
passed = show_questions(q, choices)
if passed:
m += 1
else:
m -= 1
save()
print("mastered!\n")
for_mastery()