I just wanted to share my work! Thanks to everybody for helping me in this assignment =)

assigment 1. pyhton

def seconds_difference(time_1, time_2):
    """ (number, number) -> number

    Return the number of seconds later that a time in seconds
    time_2 is than a time in seconds time_1.
        
    >>> seconds_difference(1800.0, 3600.0)
    1800.0
    >>> seconds_difference(3600.0, 1800.0)
    -1800.0
    >>> seconds_difference(1800.0, 2160.0)
    360.0
    >>> seconds_difference(1800.0, 1800.0)
    0.0
    """
    return (time_2 - time_1)

    


def hours_difference(time_1, time_2):
    """ (number, number) -> float

    Return the number of hours later that a time in seconds
    time_2 is than a time in seconds time_1.
        
    >>> hours_difference(1800.0, 3600.0)
    0.5
    >>> hours_difference(3600.0, 1800.0)
    -0.5
    >>> hours_difference(1800.0, 2160.0)
    0.1
    >>> hours_difference(1800.0, 1800.0)
    0.0
    """
    return (time_2 - time_1)/3600



def to_float_hours(hours, minutes, seconds):
    """ (int, int, int) -> float

    Return the total number of hours in the specified number
    of hours, minutes, and seconds.

    Precondition: 0 <= minutes < 60  and  0 <= seconds < 60

    >>> to_float_hours(0, 15, 0)
    0.25
    >>> to_float_hours(2, 45, 9)
    2.7525
    >>> to_float_hours(1, 0, 36)
    1.01
    """
    return(hours/1 + minutes/60 + seconds/3600)



def to_24_hour_clock(hours):
    """ (number) -> number

    hours is a number of hours since midnight. Return the
    hour as seen on a 24-hour clock.

    Precondition: hours >= 0

    >>> to_24_hour_clock(24)
    0
    >>> to_24_hour_clock(48)
    0
    >>> to_24_hour_clock(25)
    1
    >>> to_24_hour_clock(4)
    4
    >>> to_24_hour_clock(28.5)
    4.5
    """

    return hours % 24



def get_hours(seconds):
    """(int) -> int
    Return the number of hours that have elapsed since midnight.

     Precondition: seconds >= 0

    >>>get_hours(14400)
    4
    >>>get_hours(10800)
    3
    >>>get_hours(7200)
    2
    >>>get_hours(3600)
    1
    """
    return (seconds//3600)%24


def get_minutes(seconds):
    """(int) -> int
    Return the number of minutes that have elapsed
    since midnight as seen on a clock.

     Precondition: seconds >= 0
  
    >>>get_minutes(3600)
    60
    >>>get_minutes(1800)
    30
    >>>get_minutes(900)
    15
    
    """

    return (seconds//60)%60


def get_seconds(seconds):
    """ (int) -> int
    Return the number of seconds that have elapsed since midnight
    as seen on a clock.

    Precondition: seconds >= 0

    >>>get_seconds(3600)
    0
    >>>get_seconds(60)
    0
    >>>get_seconds(45)
    45
    >>>get_seconds(20)
    20
    """
    return (seconds)%60








def time_to_utc(utc_offset, time):
    """ (number, float) -> float

    Return time at UTC+0, where utc_offset is the number of hours away from
    UTC+0.

    >>> time_to_utc(+0, 12.0)
    12.0
    >>> time_to_utc(+1, 12.0)
    11.0
    >>> time_to_utc(-1, 12.0)
    13.0
    >>> time_to_utc(-11, 18.0)
    5.0
    >>> time_to_utc(-1, 0.0)
    1.0
    >>> time_to_utc(-1, 23.0)
    0.0
    """
   
    return (-utc_offset + time)%24



def time_from_utc(utc_offset, time):
    """ (number, float) -> float

    Return UTC time in time zone utc_offset.

    >>> time_from_utc(+0, 12.0)
    12.0
    >>> time_from_utc(+1, 12.0)
    13.0
    >>> time_from_utc(-1, 12.0)
    11.0
    >>> time_from_utc(+6, 6.0)
    12.0
    >>> time_from_utc(-7, 6.0)
    23.0
    >>> time_from_utc(-1, 0.0)
    23.0
    >>> time_from_utc(-1, 23.0)
    22.0
    >>> time_from_utc(+1, 23.0)
    0.0
    """
    return (utc_offset + time)%24

Assignment 2. PYTHON

 def get_length(dna):
    """ (str) -> int

    Return the length of the DNA sequence dna.

    >>> get_length('ATCGAT')
    6
    >>> get_length('ATCG')
    4
    """
    return len(dna)
  


def is_longer(dna1, dna2):
    """ (str, str) -> bool

    Return True if and only if DNA sequence dna1 is longer than DNA sequence
    dna2.

    >>> is_longer('ATCG', 'AT')
    True
    >>> is_longer('ATCG', 'ATCGGA')
    False
    """
    mod_dn1=(dna1.count('A')+ dna1.count('T')+ dna1.count('C')+ dna1.count('G'))
    mod_dn2=(dna2.count('A')+ dna2.count('T')+ dna2.count('C')+ dna2.count('G'))
    if mod_dn1>mod_dn2:
        return True
    else:
        return False

def count_nucleotides(dna, nucleotide):
    """ (str, str) -> int

    Return the number of occurrences of nucleotide in the DNA sequence dna.

    >>> count_nucleotides('ATCGGC', 'G')
    2
    >>> count_nucleotides('ATCTA', 'G')
    0
    """
    return dna.count(nucleotide)


def contains_sequence(dna1, dna2):
    """ (str, str) -> bool

    Return True if and only if DNA sequence dna2 occurs in the DNA sequence
    dna1.

    >>> contains_sequence('ATCGGC', 'GG')
    True
    >>> contains_sequence('ATCGGC', 'GT')
    False

    """
    if dna2 in dna1:
        return True
    if dna2 not in dna1:
        return False

def is_valid_sequence(dna1):
    '''(str) -> bool
 
    Return True if and only if the DNA sequence is vaild.
 
    >>> is_valid_sequence('ATCG')
    True
    >>> is_valid_sequence('FDES')
    False
    '''
 
    count = 0
    z = ['A','T','C','G']
    for elem in dna1:
      if elem not in z:
        count = count + 1
    return count == 0
 
    
def insert_sequence(dna1, dna2, int1):
    '''(str, str, int) -> str
 
    Return the DNA sequence obtained by inserting the second DNA sequence
    into the first DNA sequence at the given index.
 
    >>> insert_sequence ('ATGC', 'TGCA', 2)
    ATTGCAGC
    >>> insert_sequence ('ATGC', 'TGCA', 0)
    TGCAATGC
    '''

    return dna1[:int1] + dna2 + dna1[int1:]
 
 
def get_complement(dna):
    '''(str) -> str
    Return the nucleotide's complement.
 
    >>> get_complement('A')
    T
    >>> get_complement('C')
    G
    '''
 
    
    if dna == 'A':
        return 'T'
    elif dna == 'G':
        return 'C'
    if dna == 'T':
        return 'A'
    elif dna == 'C':
        return 'G'  
 


 def get_complementary_sequence(dna):
    '''(str) -> str
 
    Return the DNA sequence that is complementary to the given DNA
    sequence.
 
    >>> get_complementary_sequence('ATA')
    TAT
    >>> get_complementary_sequence('CGC')
    GCG
    '''

    r = ""
    for i in dna:
       
        r= r+ get_complement(i)

    return r