找出字符串中出现次数最多的字符，如果出现次数一样，输出靠前字符。python

可以使用字典来统计每个字符出现的次数，然后找出出现次数最多的字符即可。代码如下：

def find_most_frequent_char(s):
    # 统计每个字符出现的次数
    char_count = {}
    for c in s:
        if c in char_count:
            char_count[c] += 1
        else:
            char_count[c] = 1
    # 找出出现次数最多的字符
    max_count = 0
    max_char = ''
    for c, count in char_count.items():
        if count > max_count:
            max_count = count
            max_char = c
    return max_char

# 测试
s = 'abbcddd'
print(find_most_frequent_char(s)) # 输出 d

如果出现次数一样，那么我们可以用一个变量来记录当前出现次数最多的字符，然后遍历字典，如果有出现次数相同的字符，就比较它和当前最多的字符的位置，取靠前的字符。代码如下：

def find_most_frequent_char(s):
    # 统计每个字符出现的次数
    char_count = {}
    for c in s:
        if c in char_count:
            char_count[c] += 1
        else:
            char_count[c] = 1
    # 找出出现次数最多的字符
    max_count = 0
    max_char = ''
    for c, count in char_count.items():
        if count > max_count:
            max_count = count
            max_char = c
        elif count == max_count and s.index(c) < s.index(max_char):
            max_char = c
    return max_char

# 测试
s = 'abbcddd'
print(find_most_frequent_char(s)) # 输出 d

这样就能找出出现次数最多的字符了。