######################################################
### Open the file reads.fastq for reading as text
###
### Initialise a Count for the Reads.
###
### Keep reading the file one line at a time until it is empty
###
###    if the Current Line begins with an "@"
###        print it out
###        Add 1 to the Count of Reads
###
### Announce the count of Reads
###
### Close the file.
###
#######################################################

Fastq_File = open("reads.fastq","rt") # Open input file, requesting
                                      # read & text (the defaults)
                                      # explicitly

Read_Count = 0                        # Initialise Read Count

for Line in Fastq_File:       # For each Line of the fastq file, in turn,
    if Line[0] == '@':        # if it is the first line of a new read,
        print(Line, end = '') # print it out,
        Read_Count += 1       # and add 1 to the count of reads.

# Decare the Count of Reads.
print("The number of reads in the file reads.fastq is " + str(Read_Count) + ".\n\n")