在文件的特定行中查找字符

Question

I am trying to find the characters in one specific line of my code. Say the line is 4.

My file consists of:

1. randomname
2. randomname
3. 
4. 34
5. 12202018

My code consists of:

with open('/Users/eviemcmahan/PycharmProjects/eCYBERMISSION/eviemcmahan', 'r') as my_file:

data = my_file.readline(4)
characters = 0

for data in my_file:
    words = data.split(" ")
    for i in words:
        characters += len(i)

print(characters)

I am not getting an error, I am just getting the number "34"

I would appreciate any help on how to get a correct amount of characters for line 4.

Answer 1

my_file.readline(4) does not read the 4th line, instead reads the next line but only the 4 firsts characters. To read a specific line you need to, for example, read all the lines and put them in a list. Then is easy to get the line you want. You could also read line by line and stop whenever you find yourself in the line you desired.

Going with the first approach and using the count method of strings, it is straight-forward to count any character at a specific line. For example:

line_number = 3 # Starts with 0
with open('test.txt', 'r') as my_file:
  lines = my_file.readlines() # List containing all the lines as elements of the list
print(lines[line_number ].count('0')) # 0
print(lines[line_number ].count('4')) # 2