I have a text file named "paintingJobs". The data looks like this:
E5341,21/09/2015,C102,440,E,0
E5342,21/09/2015,C103,290,A,290
E5343,21/09/2015,C104,730,N,0
E5344,22/09/2015,C105,180,A,180
I have written a program that only finds the first entry but cannot find any data beyond the first line (I think it is to do with Python including /n in front of the username) The program looks like this.
def ASearch():
print("Option A: Search for an estimate")
print("Please enter the estimate number: ")
estimateNumber = str(input())
file = open("paintingJobs.txt", "r")
paintJobs = file.readlines()
file.close()
length = len(paintJobs)
paintData = []
for line in paintJobs:
estNumber, estDate, CustID, FinalTotal, Status, AmountPaid = line.split(",")
if estimateNumber == estNumber:
print("Estimate number: ", estNumber)
print("Customer ID: ", CustID)
options()#this is a function in a for a different part of the program that works fine
else:
print("You have entered an incorrect estimate number; please try again")
ASearch()
How do I get the program to read (and return the values of) the second entry in the list E.G. E5342 (any help would be appreciated greatly)
Related
I am stuck on a error that I cant seem to figure out. The program I made should ask the user for a text file and number. The program than searches the text file for that number, if it exists it should find all of its occurrences and return their line numbers. If it it doesn't it should add the number to the text file. Think you can help me?
I have already created the users input and a if statement of what should happen if found.
This is what I have:
import linecache
def Q10(name, number):
with open(name) as infile:
contents = infile.read()
if number in contents:
line_number = linecashe.getline(name, number)
print(number, "was found on line", line_number)
Q10('Q10.txt', 56)
This is the error that I got:
TypeError: 'in <string>' requires string as left operand, not int
number is an int, you need to convert it to string.
you can do it with str(int) as I showed in the code
import linecache
def Q10(name, number):
with open(name) as infile:
contents = infile.read()
if str(number) in contents:
line_number = linecashe.getline(name, number)
print(number, "was found on line", line_number)
Q10('Q10.txt', 56)
I am a beginner of python, I have an assignment that wants me to read a csv file and print out the related information.
I have an excel file which includes student's ID, school and hobby.
now I want to write a program to show the detail of the student by entering the ID.
requirements are:
print the entire row when ID is correctly input
print "Empty, try again" when ID input is space
print "No record" when the input is invalid or there is no matching record
I manage to fulfill the first 2 requirements but have no idea how to get the third. Seems like my code is always looping through each of the data and print "No record" every time, i.e. if there are 3 records, 3 "No record" will be printed. Could someone help me with it? Much thanks! Below will be my code.
import csv
file = "a.csv"
sID = input("Enter ID: ")
while (sID == " "):
print("Empty input,enter again")
sID = input("Enter ID: ")
with open(file) as csvfile:
reader = csv.DictReader(csvfile)
for row in reader:
if (sID == row["id"]):
print("{0}{1}{2}".format(row[id],row[school],row[hobby])
else:
print("No record")
You need a few changes:
You should use the str.strip() method to test if a string is empty so that it accounts for any number of spaces.
You should quote the column names to make them string literals when using them as indices to access the value of a column in the current row.
You should use the optional else block for your for loop to determine that there is no matching record found, and break the loop if there is one found.
You are missing a right parenthesis for the print call that outputs a row.
With the above changes, your code should look like:
import csv
file = "a.csv"
sID = input("Enter ID: ")
while not sID.strip():
print("Empty input,enter again")
sID = input("Enter ID: ")
with open(file) as csvfile:
reader = csv.DictReader(csvfile)
for row in reader:
if (sID == row["id"]):
print("{0}{1}{2}".format(row['id'],row['school'],row['hobby']))
break
else:
print("No record")
I am trying to pull a string of input names that get saved to a text file. I need to pull them by capital letter which is input. I.E. the saved text file contains names DanielDanClark, and I need to pull the names that begin with D. I am stuck at this part
for i in range(num):
print("Name",i+1," >> Enter the name:")
n=input("")
names+=n
file=open("names.txt","w")
file.write(names)
lookUp=input("Did you want to look up any names?(Y/N)")
x= ord(lookUp)
if x == 110 or x == 78:
quit()
else:
letter=input("Enter the first letter of the names you want to look up in uppercase:")
file=open("names.txt","r")
fileNames=[]
file.list()
for letter in file:
fileNames.index(letter)
fileNames.close()
I know that the last 4 lines are probably way wrong. It is what I tried in my last failed attempt
Lets break down your code block by block
num = 5
names = ""
for i in range(num)
print("Name",i+1," >> Enter the name:")
n=input("")
names+=n
I took the liberty of giving num a value of 5, and names a value of "", just so the code will run. This block has no problems. And will create a string called names with all the input taken. You might consider putting a delimiter in, which makes it more easier to read back your data. A suggestion would be to use \n which is a line break, so when you get to writing the file, you actually have one name on each line, example:
num = 5
names = ""
for i in range(num)
print("Name",i+1," >> Enter the name:")
n = input()
names += n + "\n"
Now you are going to write the file:
file=open("names.txt","w")
file.write(names)
In this block you forget to close the file, and a better way is to fully specify the pathname of the file, example:
file = open(r"c:\somedir\somesubdir\names.txt","w")
file.write(names)
file.close()
or even better using with:
with open(r"c:\somedir\somesubdir\names.txt","w") as openfile:
openfile.write(names)
The following block you are asking if the user want to lookup a name, and then exit:
lookUp=input("Did you want to look up any names?(Y/N)")
x= ord(lookUp)
if x == 110 or x == 78:
quit()
First thing is that you are using quit() which should not be used in production code, see answers here you really should use sys.exit() which means you need to import the sys module. You then proceed to get the numeric value of the answer being either N or n and you check this in a if statement. You do not have to do ord() you can use a string comparisson directly in your if statement. Example:
lookup = input("Did you want to look up any names?(Y/N)")
if lookup.lower() == "n":
sys.exit()
Then you proceed to lookup the requested data, in the else: block of previous if statement:
else:
letter=input("Enter the first letter of the names you want to look up in uppercase:")
file=open("names.txt","r")
fileNames=[]
file.list()
for letter in file:
fileNames.index(letter)
fileNames.close()
This is not really working properly either, so this is where the delimiter \n is coming in handy. When a text file is opened, you can use a for line in file block to enumerate through the file line by line, and with \n delimiter added in your first block, each line is a name. You also go wrong in the for letter in file block, it does not do what you think it should be doing. It actually returns each letter in the file, regardless of whay you type in the input earlier. Here is a working example:
letter = input("Enter the first letter of the names you want to look up in uppercase:")
result = []
with open(r"c:\somedir\somesubdir\names.txt", "r") as openfile:
for line in openfile: ## loop thru the file line by line
line = line.strip('\n') ## get rid of the delimiter
if line[0].lower() == letter.lower(): ## compare the first (zero) character of the line
result.append(line) ## append to result
print(result) ## do something with the result
Putting it all together:
import sys
num = 5
names = ""
for i in range(num)
print("Name",i+1," >> Enter the name:")
n = input("")
names += n + "\n"
with open(r"c:\somedir\somesubdir\names.txt","w") as openfile:
openfile.write(names)
lookup = input("Did you want to look up any names?(Y/N)")
if lookup.lower() == "n":
sys.exit()
letter = input("Enter the first letter of the names you want to look up in uppercase:")
result = []
with open(r"c:\somedir\somesubdir\names.txt", "r") as openfile:
for line in openfile:
line = line.strip('\n')
if line[0].lower() == letter.lower():
result.append(line)
print(result)
One caveat I like to point out, when you create the file, you open the file in w mode, which will create a new file every time, therefore overwriting the a previous file. If you like to append to a file, you need to open it in a mode, which will append to an existing file, or create a new file when the file does not exist.
In our class we were given the task to basically create a program that re-enacts the US election last year. One of the extra challenges is that when you enter an ID number that is already in the file, it should come up with an error and just stop. However, when I try to execute this code, it comes up with
ValueError: I/O operation on closed file.
This is the code I've done so far...
ID = input("Please input ID code ")
if(len(ID)) == 6:
print("ID length: Valid")
N += 1
else:
print("ID Code: Error")
sys.exit()
with open('ID.txt', 'a') as idc:
idc.write(ID + ' ')
already_seen = set()
for line in idc:
if line not in already_seen:
print("Valid")
else:
print("Error")
sys.exit()
Thanks
You should know the difference between the
with open('ID.txt', 'a') as idc:
do sth
and the
idc = open('ID.txt', 'a')
In the first case, after the do sth finished, the __exit__() of the idc will be called to close the file object.
I advise you to use the second expression that I indicate above. If you are new to Python, this blog will help you to understand the detail reasons.
I need to make a program in a single def that opens a text file 'grades' where first, last and grade are separated by comas. Each line is a separate student. Then it displays students and grades as well as class average. Then goes on to add another student and grade and saves it to the text file while including the old students.
I guess I just don't understand the way python goes through the text file. If i comment out 'lines' I see it prints the old_names but its as if everything is gone after. When lines is not commented out 'old_names' is not printed which makes me think the file is closed? or empty? however everything is still in the txt file as it should be.
currently i get this error.... Which I am pretty sure is telling me I'm retarded there's no information in 'line'
File "D:\Dropbox\Dropbox\1Python\Batch Processinga\grades.py", line 45, in main
first_name[i], last_name[i], grades[i] = line.split(',')
ValueError: need more than 1 value to unpack
End goal is to get it to give me the current student names and grades, average. Then add one student, save that student and grade to file. Then be able to pull the file back up with all the students including the new one and do it all over again.
I apologize for being a nub.
def main():
#Declare variables
#List of strings: first_name, last_name
first_name = []
last_name = []
#List of floats: grades
grades = []
#Float grade_avg, new_grade
grade_avg = new_grade = 0.0
#string new_student
new_student = ''
#Intro
print("Program displays information from a text file to")
print("display student first name, last name, grade and")
print("class average then allows user to enter another")
print("student.\t")
#Open file “grades.txt” for reading
infile = open("grades.txt","r")
lines = infile.readlines()
old_names = infile.read()
print(old_names)
#Write for loop for each line creating a list
for i in len(lines):
#read in line
line = infile.readline()
#Split data
first_name[i], last_name[i], grades[i] = line.split(',')
#convert grades to floats
grades[i] = float(grades[i])
print(first_name, last_name, grades)
#close the file
infile.close()
#perform calculations for average
grade_avg = float(sum(grades)/len(grades))
#display results
print("Name\t\t Grade")
print("----------------------")
for n in range(5):
print(first_name[n], last_name[n], "\t", grades[n])
print('')
print('Average Grade:\t% 0.1f'%grade_avg)
#Prompt user for input of new student and grade
new_student = input('Please enter the First and Last name of new student:\n').title()
new_grade = eval(input("Please enter {}'s grade:".format(new_student)))
#Write new student and grade to grades.txt in same format as other records
new_student = new_student.split()
new_student = str(new_student[1] + ',' + new_student[0] + ',' + str(new_grade))
outfile = open("grades.txt","w")
print(old_names, new_student ,file=outfile)
outfile.close()enter code here
File objects in Python have a "file pointer", which keeps track of what data you've already read from the file. It uses this to know where to start looking when you call read or readline or readlines. Calling readlines moves the file pointer all the way to the end of the file; subsequent read calls will return an empty string. This explains why you're getting a ValueError on the line.split(',') line. line is an empty string, so line.split(",") returns a list of length 0, but you need a list of length 3 to do the triple assignment you're attempting.
Once you get the lines list, you don't need to interact with the infile object any more. You already have all the lines; you may as well simply iterate through them directly.
#Write for loop for each line creating a list
for line in lines:
columns = line.split(",")
first_name.append(columns[0])
last_name.append(columns[1])
grades.append(float(columns[2]))
Note that I'm using append instead of listName[i] = whatever. This is necessary because Python lists will not automatically resize themselves when you try to assign to an index that doesn't exist yet; you'll just get an IndexError. append, on the other hand, will resize the list as desired.