We Keep Coding

Same python code block gives different outputs at different time

I want to create a word dictionary. The dictionary looks like
words_meanings= {
"rekindle": "relight",
"pesky":"annoying",
"verge": "border",
"maneuver": "activity",
"accountability":"responsibility",
}
keys_letter=[]
for x in words_meanings:
keys_letter.append(x)
print(keys_letter)
Output: rekindle , pesky, verge, maneuver, accountability
Here rekindle , pesky, verge, maneuver, accountability they are the keys and relight, annoying, border, activity, responsibility they are the values.
Now I want to create a csv file and my code will take input from the file.
The file looks like
rekindle | pesky | verge | maneuver | accountability
relight | annoying| border| activity | responsibility
So far I use this code to load the file and read data from it.
from google.colab import files
uploaded = files.upload()
import pandas as pd
data = pd.read_csv("words.csv")
data.head()
import csv
reader = csv.DictReader(open("words.csv", 'r'))
words_meanings = []
for line in reader:
words_meanings.append(line)
print(words_meanings)
This is the output of print(words_meanings)
[OrderedDict([('\ufeffrekindle', 'relight'), ('pesky', 'annoying')])]
It looks very odd to me.
keys_letter=[]
for x in words_meanings:
keys_letter.append(x)
print(keys_letter)
Now I create an empty list and want to append only key values. But the output is [OrderedDict([('\ufeffrekindle', 'relight'), ('pesky', 'annoying')])]
I am confused. As per the first code block it only included keys but now it includes both keys and their values. How can I overcome this situation?

I would suggest that you format your csv with your key and value on the same row. Like this
rekindle,relight
pesky,annoying
verge,border
This way the following code will work.
words_meanings = {}
with open(file_name, 'r') as file:
for line in file.readlines():
key, value = line.split(",")
word_meanings[key] = value.rstrip("\n")
if you want a list of the keys:
list_of_keys = list(word_meanings.keys())
To add keys and values to the file:
def add_values(key:str, value:str, file_name:str):
with open(file_name, 'a') as file:
file.writelines(f"\n{key},{value}")
key = input("Input the key you want to save: ")
value = input(f"Input the value you want to save to {key}:")
add_values(key, value, file_name)```

You run the same block of code but you use it with different objects and this gives different results.
First you use normal dictionary (check type(words_meanings))
words_meanings = {
"rekindle": "relight",
"pesky":"annoying",
"verge": "border",
"maneuver": "activity",
"accountability":"responsibility",
}
and for-loop gives you keys from this dictionary
You could get the same with
keys_letter = list(words_meanings.keys())
or even
keys_letter = list(words_meanings)
Later you use list with single dictionary inside this list (check type(words_meanings))
words_meanings = [OrderedDict([('\ufeffrekindle', 'relight'), ('pesky', 'annoying')])]
and for-loop gives you elements from this list, not keys from dictionary which is inside this list. So you move full dictionary from one list to another.
You could get the same with
keys_letter = words_meanings.copy()
or even the same
keys_letter = list(words_meanings)
from collections import OrderedDict
words_meanings = {
"rekindle": "relight",
"pesky":"annoying",
"verge": "border",
"maneuver": "activity",
"accountability":"responsibility",
}
print(type(words_meanings))
keys_letter = []
for x in words_meanings:
keys_letter.append(x)
print(keys_letter)
#keys_letter = list(words_meanings.keys())
keys_letter = list(words_meanings)
print(keys_letter)
words_meanings = [OrderedDict([('\ufeffrekindle', 'relight'), ('pesky', 'annoying')])]
print(type(words_meanings))
keys_letter = []
for x in words_meanings:
keys_letter.append(x)
print(keys_letter)
#keys_letter = words_meanings.copy()
keys_letter = list(words_meanings)
print(keys_letter)

The default field separator for the csv module is a comma. Your CSV file uses the pipe or bar symbol |, and the fields also seem to be fixed width. So, you need to specify | as the delimiter to use when creating the CSV reader.
Also, your CSV file is encoded as Big-endian UTF-16 Unicode text (UTF-16-BE). The file contains a byte-order-mark (BOM) but Python is not stripping it off, so you will notice the string '\ufeffrekindle' contains the FEFF UTF-16-BE BOM. That can be dealt with by specifying encoding='utf16' when you open the file.
import csv
with open('words.csv', newline='', encoding='utf-16') as f:
reader = csv.DictReader(f, delimiter='|', skipinitialspace=True)
for row in reader:
print(row)
Running this on your CSV file produces this:
{'rekindle ': 'relight ', 'pesky ': 'annoying', 'verge ': 'border', 'maneuver ': 'activity ', 'accountability': 'responsibility'}
Notice that there is trailing whitespace in the key and values. skipinitialspace=True removed the leading whitespace, but there is no option to remove the trailing whitespace. That can be fixed by exporting the CSV file from Excel without specifying a field width. If that can't be done, then it can be fixed by preprocessing the file using a generator:
import csv
def preprocess_csv(f, delimiter=','):
# assumes that fields can not contain embedded new lines
for line in f:
yield delimiter.join(field.strip() for field in line.split(delimiter))
with open('words.csv', newline='', encoding='utf-16') as f:
reader = csv.DictReader(preprocess_csv(f, '|'), delimiter='|', skipinitialspace=True)
for row in reader:
print(row)
which now outputs the stripped keys and values:
{'rekindle': 'relight', 'pesky': 'annoying', 'verge': 'border', 'maneuver': 'activity', 'accountability': 'responsibility'}

As I found that no one able to help me with the answer. Finally, I post the answer here. Hope this will help other.
import csv
file_name="words.csv"
words_meanings = {}
with open(file_name, newline='', encoding='utf-8-sig') as file:
for line in file.readlines():
key, value = line.split(",")
words_meanings[key] = value.rstrip("\n")
print(words_meanings)
This is the code to transfer a csv to a dictionary. Enjoy!!!

Python reading in integers from a csv file into a list

I am having some trouble trying to read a particular column in a csv file into a list in Python. Below is an example of my csv file:
Col 1 Col 2
1,000,000 1
500,000 2
250,000 3
Basically I am wanting to add column 1 into a list as integer values and am having a lot of trouble doing so. I have tried:
for row in csv.reader(csvfile):
list = [int(row.split(',')[0]) for row in csvfile]
However, I get a ValueError that says "invalid literal for int() with base 10: '"1'
I then tried:
for row in csv.reader(csvfile):
list = [(row.split(',')[0]) for row in csvfile]
This time I don't get an error however, I get the list:
['"1', '"500', '"250']
I have also tried changing the delimiter:
for row in csv.reader(csvfile):
list = [(row.split(' ')[0]) for row in csvfile]
This almost gives me the desired list however, the list includes the second column as well as, "\n" after each value:
['"1,000,000", 1\n', etc...]
If anyone could help me fix this it would be greatly appreciated!
Cheers

You should choose your delimiter wisely :
If you have floating numbers using ., use , delimiter, or if you use , for floating numbers, use ; as delimiter.
Moreover, as referred by the doc for csv.reader you can use the delimiter= argument to define your delimiter, like so:
with open('myfile.csv', 'r') as csvfile:
mylist = []
for row in csv.reader(csvfile, delimiter=';'):
mylist.append(row[0]) # careful here with [0]
or short version:
with open('myfile.csv', 'r') as csvfile:
mylist = [row[0] for row in csv.reader(csvfile, delimiter=';')]
To parse your number to a float, you will have to do
float(row[0].replace(',', ''))

You can open the file and split at the space using regular expressions:
import re
file_data = [re.split('\s+', i.strip('\n')) for i in open('filename.csv')]
final_data = [int(i[0]) for i in file_data[1:]]

First of all, you must parse your data correctly. Because it's not, in fact, CSV (Comma-Separated Values) but rather TSV (Tab-Separated) of which you should inform CSV reader (I'm assuming it's tab but you can theoretically use any whitespace with a few tweaks):
for row in csv.reader(csvfile, delimiter="\t"):
Second of all, you should strip your integer values of any commas as they don't add new information. After that, they can be easily parsed with int():
int(row[0].replace(',', ''))
Third of all, you really really should not iterate the same list twice. Either use a list comprehension or normal for loop, not both at the same time with the same variable. For example, with list comprehension:
csvfile = StringIO("Col 1\tCol 2\n1,000,000\t1\n500,000\t2\n250,000\t3\n")
reader = csv.reader(csvfile, delimiter="\t")
next(reader, None) # skip the header
lst = [int(row[0].replace(',', '')) for row in reader]
Or with normal iteration:
csvfile = StringIO("Col 1\tCol 2\n1,000,000\t1\n500,000\t2\n250,000\t3\n")
reader = csv.reader(csvfile, delimiter="\t")
lst = []
for i, row in enumerate(reader):
if i == 0:
continue # your custom header-handling code here
lst.append(int(row[0].replace(',', '')))
In both cases, lst is set to [1000000, 500000, 250000] as it should. Enjoy.
By the way, using reserved keyword list as a variable is an extremely bad idea.
UPDATE. There's one more option that I find interesting. Instead of setting the delimiter explicitly you can use csv.Sniffer to detect it e.g.:
csvdata = "Col 1\tCol 2\n1,000,000\t1\n500,000\t2\n250,000\t3\n"
csvfile = StringIO(csvdata)
dialect = csv.Sniffer().sniff(csvdata)
reader = csv.reader(csvfile, dialect=dialect)
and then just like the snippets above. This will continue working even if you replace tabs with semicolons or commas (would require quotes around your weird integers) or, possibly, something else.

Copying CSV File when integer exceeds maximum

If this input exists in a specific row, for example DD in row WORD4 (row 3), the program will then ask them to enter an integer and if this is over a certain number it will write it including the line.
Something like so:
a0,a1,a2,a3,a4
JA,BV,PA,DD,6
The error received I did receive was:
TypeError: writerows() takes exactly one argument (2 given)
And
TypeError: can only concatenate list (not "str") to list
Thanks to Joel Johnson and Stevieb for the solution to this problem!
The solution is as followed, Thanks Joel Johnson:

First, you need to use with open('CSVFile2.csv', 'a') as f: to write anything to the file(if you want to keep any content already in CSVFile2.csv or use 'w' if you want to overwrite it).
Second, since you are only trying to write one row with format
['JA',BV','PA','DD','6'] use writer.writerow() instead of writer.writerows() else you will end up with J,A,B,V,P,A,D,D,6 as your output.
Third, simply append integer_input to row before passing it to writer.writerow() also note that it needs to be in str() format
If you have any other questions I would refer you to the docs here
example:
with open('CSVFile1.csv', "rb") as csvfile:
a = csv.reader(csvfile, delimiter=',')
for row in a:
if user_input in row[3] and integer_input>5:
with open('CSVFile2.csv', 'a') as f:
new_row = row
new_row.append(str(integer_input))
writer = csv.writer(f)
writer.writerow(new_row)
f.close()

writerows() does only take one parameter. The below code appends the row[3] to the row, then the entire row is sent to writerow() as its only parameter. I've also moved the writer file to outside of the loop, otherwise if more than one match occurs, you'd be overwriting it on each iteration.
with open('CSVFile1.csv', 'rb') as csvfile:
fh = csv.reader(csvfile)
wfh = open('CSVFile2.csv', 'ab')
for row in fh:
if user_input in row[3] and int(integer_input) > 5:
row.append(integer_input)
writer = csv.writer(wfh)
writer.writerow(row)
wfh.close()

Remove double quotes from iterator when using csv writer

I want to create a csv from an existing csv, by splitting its rows.
Input csv:
A,R,T,11,12,13,14,15,21,22,23,24,25
Output csv:
A,R,T,11,12,13,14,15
A,R,T,21,22,23,24,25
So far my code looks like:
def update_csv(name):
#load csv file
file_ = open(name, 'rb')
#init first values
current_a = ""
current_r = ""
current_first_time = ""
file_content = csv.reader(file_)
#LOOP
for row in file_content:
current_a = row[0]
current_r = row[1]
current_first_time = row[2]
i = 2
#Write row to new csv
with open("updated_"+name, 'wb') as f:
writer = csv.writer(f)
writer.writerow((current_a,
current_r,
current_first_time,
",".join((row[x] for x in range(i+1,i+5)))
))
#do only one row, for debug purposes
return
But the row contains double quotes that I can't get rid of:
A002,R051,02-00-00,"05-21-11,00:00:00,REGULAR,003169391"
I've tried to use writer = csv.writer(f,quoting=csv.QUOTE_NONE) and got a _csv.Error: need to escape, but no escapechar set.
What is the correct approach to delete those quotes?

I think you could simplify the logic to split each row into two using something along these lines:
def update_csv(name):
with open(name, 'rb') as file_:
with open("updated_"+name, 'wb') as f:
writer = csv.writer(f)
# read one row from input csv
for row in csv.reader(file_):
# write 2 rows to new csv
writer.writerow(row[:8])
writer.writerow(row[:3] + row[8:])

writer.writerow is expecting an iterable such that it can write each item within the iterable as one item, separate by the appropriate delimiter, into the file. So:
writer.writerow([1, 2, 3])
would write "1,2,3\n" to the file.
Your call provides it with an iterable, one of whose items is a string that already contains the delimiter. It therefore needs some way to either escape the delimiter or a way to quote out that item. For example,
write.writerow([1, '2,3'])
Doesn't just give "1,2,3\n", but e.g. '1,"2,3"\n' - the string counts as one item in the output.
Therefore if you want to not have quotes in the output, you need to provide an escape character (e.g. '/') to mark the delimiters that shouldn't be counted as such (giving something like "1,2/,3\n").
However, I think what you actually want to do is include all of those elements as separate items. Don't ",".join(...) them yourself, try:
writer.writerow((current_a, current_r,
current_first_time, *row[i+2:i+5]))
to provide the relevant items from row as separate items in the tuple.

How do I create add new items to a dictionary while in a loop?

I'm writing a program that reads names and statistics related to those names from a file. Each line of the file is another person and their stats. For each person, I'd like to make their last name a key and everything else linked to that key in the dictionary. The program first stores data from the file in an array and then I'm trying to get those array elements into the dictionary, but I'm not sure how to do that. Plus I'm not sure if each time the for loop iterates, it will overwrite the previous contents of the dictionary. Here's the code I'm using to attempt this:
f = open("people.in", "r")
tmp = None
people
l = f.readline()
while l:
tmp = l.split(',')
print tmp
people = {tmp[2] : tmp[0])
l = f.readline()
people['Smith']
The error I'm currently getting is that the syntax is incorrect, however I have no idea how to transfer the array elements into the dictionary other than like this.

Use key assignment:
people = {}
for line in f:
tmp = l.rstrip('\n').split(',')
people[tmp[2]] = tmp[0]
This loops over the file object directly, no need for .readline() calls here, and removes the newline.
You appear to have CSV data; you could also use the csv module here:
import csv
people = {}
with open("people.in", "rb") as f:
reader = csv.reader(f)
for row in reader:
people[row[2]] = row[0]
or even a dict comprehension:
import csv
with open("people.in", "rb") as f:
reader = csv.reader(f)
people = {r[2]: r[0] for r in reader}
Here the csv module takes care of the splitting and removing newlines.
The syntax error stems from trying close the opening { with a ) instead of }:
people = {tmp[2] : tmp[0]) # should be }
If you need to collect multiple entries per row[2] value, collect these in a list; a collections.defaultdict instance makes that easier:
import csv
from collections import defaultdict
people = defaultdict(list)
with open("people.in", "rb") as f:
reader = csv.reader(f)
for row in reader:
people[row[2]].append(row[0])

In repsonse to Generalkidd's comment above, multiple people with the same last time, an addition to Martijn Pieter's solution, posted as an answer for better formatting:
import csv
people = {}
with open("people.in", "rb") as f:
reader = csv.reader(f)
for row in reader:
if not row[2] in people:
people[row[2]] = list()
people[row[2]].append(row[0])